Pdf vault

1. assignment (inelastic collision)

Assignment text: Two cars approach an intersection at a right angle to each other. If an inelastic collision occurs at the intersection, determine the x component of the final momentum of the combined vehicles. Car1 of mass 1,117.38 kg approaches the intersection from the left with a speed of 22.53 m/s. Car 2 of mass 1,195.19 kg approaches the intersection from the south with a speed of 16.27 m/s.

2. assignment (elastic collision)

Assignment text: A 0.151 kg glider is moving to the right with a speed of 0.88 m/s on a frictionless horizontal air track. The glider has a collision with a 0.301 kg glider that is moving to the left with a speed of 2.3 m/s. Find the final velocity of each glider if the collision is elastic.

3. assignment (light wavelength)

Assignment text: Blue-green light has a frequency of about 6*10^14 Hz. Using relation C=f λ where C is the speed of light in air and is 3*10^8 m/s, find its wavelength in air. How much bigger is the blue-green wavelength compared to the size of an atom, which is about 10^-10 m?

4. assignment (mass spectrometer)

Assignment text: Two isotopes of carbon, carbon-12 and carbon-13, have masses of 19.93 × 10-27 kg and 21.59 × 10-27 kg, respectively. These two isotopes are singly ionized (+e) and each is given a speed of 7.287 × 105 m/s. The ions then enter the bending region of a mass spectrometer where the magnetic field is 0.7501 T. Determine the spatial separation between the two isotopes after they have traveled through a half-circle. Use 1.602 × 10-19 C as the elementary charge and give your answer to four significant figures.

5. assignment (reactance, capacitance)

Assignment text: A 34.0-mH inductor has a reactance of 2.00 k?. (a) What is the frequency of the ac current that passes through the inductor? ___________ Hz (b) What is the capacitance of a capacitor that has the same reactance at this frequency? _________ F (c) The frequency is tripled, so that the reactances of the inductor and capacitor are no longer equal. What is the new reactance of the inductor? _________ k? (d) What is the new reactance of the capacitor? ________ k?

6. assignment (rotational dynamics)

Assignment text: As seen from above in the image, a string is wrapped around the edge of a uniform cylinder of radius R = 27 cm and mass M = 1 kg which is initially resting motionless on a frictionless table. The end of the string is pulled with a force of 72 N for 0.8 m. If the linear speed of the cylinder is found to be 6.19677 m/s, what is the angular speed of the cylinder (in rad/s)? Answer in units of rad/s.

7. assignment (inelastic collision)

Assignment text: Two asteroids of equal mass in the asteroid belt between Mars and Jupiter collide with a glancing blow. Asteroid A, which was initially traveling at 40.0 m/s, is deflected 30.0° from its original direction, while asteroid B, which was initially at rest, travels at 45.0° to the original direction of A (Fig. E8.31). (a) Find the speed of each asteroid after the collision. (b) What fraction of the original kinetic energy of asteroid A dissipates during this collision?

8. assignment (peak current)

Assignment text: An AC heater has an average power of 1410 W. It runs on 160 V rms. What is the peak current through the heater?

9. assignment (torque equilibrium)

Assignment text: A 61.5 kg painter is on a uniform 25.5 kg scaffold supported from above by ropes. There is a 5.0 kg pail of paint to one side, as shown. How close to the end can he approach safely?

10. assignment (mass energy relation)

Assignment text: For each of the scenarios below, determine how the total mass of the described object or system is changing, and place in the appropriate bin.

11. assignment (inclined plane)

Assignment text: The figure shows two packages that start sliding down a 20° ramp from rest a distance d = 7.0 m along the ramp from the bottom. Package A has a mass of 2.5 kg and a coefficient of kinetic friction 0.20 between it and the ramp. Package B has a mass of 8.0 kg and a coefficient of kinetic friction 0.10 between it and the ramp. What is the force of friction, in Newtons, on the 2 boxes. Give your answer in the format: (friction on A, friction on B) What is the acceleration of box B as it slides down the ramp? What force does box A exert on box B as they slide down the ramp? How long does it take box B to slide down the ramp?

12. assignment (simple harmonic motion)

Assignment text: A 500 g block on a frictionless surface is attached to a rather limp spring of constant k = 8.7 N/m. A second block rests on the first, and the whole system executes simple harmonic motion with a period of 3.5 s. When the amplitude of the motion is increased to 68 cm, the upper block just begins to slip. What is the coefficient of static friction between the blocks?

13. assignment (Carnot engine)

1. A nonideal engine operating between the same temperature extremes as a Carnot engine and having the same input thermal energy will perform the same amount of work as the Carnot engine. Explain. (Select all that apply.)
2. The Carnot engine is a model that accurately describes all heat engines.
3. Carnot engines do not really exist. All real engines are less efficient.
4. The efficiency of any heat engine is determined only by its input and output temperatures
5. Since the Carnot engine has the greatest efficiency possible, other engines operating between the two temperatures produce less useful work output for the same work input.
6. All other engines operating between the two temperatures produce more useful work output than the Carnot engine for the same work input.

14. assignment (voltage law)

Assignment text: Find the current in the circuit branches in the figure below, where R1 = 2.0 Ohms , R2 = 4.0 Ohms , R3 = 4.0 Ohms , R4 = 2.0 Ohms , R5 = 7.0 Ohms , R6 = 6.0 Ohms , V1= 20 V, and V2 = 5 V. IR1= ...

15. assignment (thermal expansion)

Assignment text: an aluminum alloy hollow metal sphere ( alpha=25x10^-6/C) with a radius of 1 meter is exposed to a 111C temperature increased. what is the percent increased of its volume?

16. assignment (De Broglie wavelength)

Assignment text: The distance between atoms in a solid is usually around 2.0*10^-10 m. Because this is much smaller than the wavelength of visible light, visible light cannot be used to study the structure of solids. X-rays and electrons are commonly used. What is the wavelength of an electron with a kinetic energy of 130 eV? Mass of electron: 9.11*10^-31kg What is the energy of a photon with the same wavelength of the electron of the above problem?

17. assignment (particle decay)

Assignment text: In a decay of 90Th232 by emission of an alpha particle, the daughter nucleus will be a. 92U232. b. 87Ac232. c. 88Ra228. d. 90Th228.

18. assignment (lensmaker's equation.)

Assignment text: If the lens is equiconvex and has index of refraction(n)1.50, find the magnitude of it's radii of curvature. In order to do this you will use the Lensmaker's Equation. In this equation f is the focal length of the lens: 5.19 cm n is the index of refraction:1.50 r1and r2 are the radii of curvature of the front and back surface of the lens, If the lens is equiconvex then r1= r2, write down the Lensmakers Equation... Calculate the Radius of lens curvature and show all work.

19. assignment (rotational dynamics)

A wheel of radius r1 = 0.8 m and hub of radius r2 = 0.4 m is shown in the diagram. Two masses are hung from the wheel-hub system. The mass m2, on the left, is hung from the hub. The mass m1 is hung from the wheel. The system is in equilibrium. The moment of inertia for the disk-hub system is I = 1.34 kg m2. 1. Which of the following statements are true: a. m1 = m2 b. m1 less-than m2 c. m1 greater than m2 2. The mass m2 = 1.6 kg. What is the mass of m1? 3. If m1 = 0.88 kg is large enough for the system to rotate, when m2 = 1.6 kg, what is the magnitude of the acceleration of the mass m2?

20. assignment (Snell's law)

Assignment text: One light ray from a fish dorsal fin-tip under-water (n=4/3) enters air at x=0 exactly along the Normal ; another light ray from the fin-tip enters air at x=0.1 [m] , at a 5.0° angle from the water surface Normal. Snell will tell you where the light is really coming from, so you can use a trig triangle to determine how deep the fish really is. follow-up: trace-back straight along the 5° line to make a "virtual right triangle" of how deep the fish appears to be; is the fish deeper or shallower than it appears to be? by what factor?

21. assignment ( mass spectrometry)

Assignment text: (a)In what fundamental way is mass spectrometry related to Thomson’s cathode-ray experiments? (b) What are the labels on the axes of a mass spectrum? (c)To measure the mass spectrum of an atom, the atom must first lose one or more electrons. Why is this so?

22. assignment (induced emf-metal bar)

Assignment text: A 2.00-m-long metal bar is pulled to the right at a steady 4.7m/s perpendicular to a uniform, 0.770-T magnetic field. The bar rides on parallel metal rails connected through R = 25.6 , as shown in the figure (Figure 1) , so the apparatus makes a complete circuit. You can ignore the resistance of the bar and the rails. Part A Calculate the magnitude of the emf induced in the circuit. Express your answer using two significant figures. E = Part B Find the direction of the current induced in the circuit. Find the direction of the current induced in the circuit. Part C Calculate the current through the resistor. Express your answer using two significant figures. I =

23. assignments (radioactive decay-dating

Assignment text: Radioactive decay can be used to determine the age of an object. If you know the number of radioactive nuclei with which an object started, the number of radioactive nuclei currently present, and the half-life of the isotope, you can calculate the time since the object was created. Suppose an object was created with 3.850×109 nuclei of a particular isotope that has a half-life of 1.60×103 yr. At this point in time 1.078×109 nuclei of this particular isotope remain.

24. assignment (activity of the radioactive material)

Assignment text: A device used in radiation therapy for cancer contains 1.40 g of cobalt 2760Co (59.9333819 u). The half-life of 2760Co is 6.69 yr. Determine the activity of the radioactive material.

25. assignments (Ohm's law)

Assignment text: A resistor has a potential difference of 6.05 volts applied across it, and a current of 345 mA flows through it. What is its resistance?

26. assignment (centripetal acceleration)

Assignment text: A bob on a 0.6m long string is rotated in a vertical circle. When the bob is in the position when the string makes a 45 degree angle above the horizontal, centripetal acceleration is 28m/s^2. Find the tangential acceleration at this point and the speed of the bob at the top point of the circle.

27. assignment (ball on a string)

Assignment text: A girl rotates a ball on a string in uniform circular motion above her head in a horizontal circular. Next she increases the tension force to twice its original value while keeping the radius constant. How is the new motion different from before? That is, what other parameter is higher or lower?

28. assignment (magnifying glass)

Assignment text: Sherlock Holmes is using a 13.4 cm focal length lens as his magnifying glass. To obtain maximum magnification, how far away must the object be placed (assume a normal eye)? What will be the magnification?

29. assignment (quark)

Assignment text: The K– particle has a charge of -e and contains one quark and one antiquark. (a) Which quarks can the particle not contain? (b) Which antiquarks can the particle not contain?

30. assignment (elastic collision)

Assignment text: A white billiard ball with mass mW = 1.59 kg is moving directly to the right with a speed of v=2.93 m/s and collides elastically with a black billiard ball with the same mass mB = 1.59 kg that is initially at rest. The two collide elastically and the white ball ends up moving at an angle above the horizontal of θW=410 and the black ball ends up moving at an angle below the horizontal of θB=410 . 1. What is the final speed of the white ball? 2. What is the final speed of the black ball? 3. What is the magnitude of the final total momentum of the system? 4. What is the final total energy of the system?

31. assignments (laser-prism)

Assignment text: What happens when a laser passes through a prism?

32. assignments (refraction)

Assignment text: A container, crown class (n=1.52), holds a small quantity of ethyl alcohol (n=1.361) what is the critical angle for internal reflection of a ray in the glass when it is incident on the glass to liquid surface? A different liquid is poured into the container and the critical angle for internal reflection is measured to be 53.2 degrees. What is the index of refraction of this liquid?

33. assignments (magnetic force)

Assignment text: A wire 60.0 mm long is bent in a right angle such that the wire starts at the origin and goes in a straight line to x = 25.0 mm , y = 0, and then in another straight line from x = 25.0 mm , y = 0 to x = 25.0 mm , y = 35.0mm . The wire is in an external uniform 0.400 T magnetic field in the +z direction, and the current through the wire is 4.70 A, directed from the origin into the wire. Determine the magnitude of the magnetic force exerted by the external field on the wire.

34. assignment (travelling wave )

Assignment text: A string along which waves can travel is 2.70 m long and has a mass of 260.0 g. The tension in the string is 36.0 N. What must be the frequency of traveling waves of amplitude 7.70 mm for the average power to be 11.0 W?

35. assignments (vector algebra)

Given the vectors A=3i – 4j and B=-2i+2j. Find a) the magnitude b) the direction c) the components of I) 2A+3B II) A-B III) -2A-2B

36. assignment (diffraction grating )

Assignment text: A diffraction grating has 2800 lines/cm. What is the angle between the second-order maxima for red light (lambda = 695 nm) and blue light (lambda = 410 nm)?

37. assignments ( electromotive force )

Assignment text: Based on a sliding rod generator in the diagram that is being pulled to the left at constant speed what is the direction of the current through the resistor, what is the speed of the rod, and how much force must be put on the rod? L=33 cm, B=0.55T, R=6 ohm, and I=3.0mA

38. assignment (continuity equation)

Assignment text: A garden hose having an internal diameter of 0.710 in. ( 1.8034 cm ) is connected to a lawn sprinkler that consists merely of an enclosure with 24 holes, each 0.050 in. ( 0.1270 cm ) in diameter. If the water in the hose has a speed of 2.67 ft/s ( 81.280 cm/s ), at what speed does it leave the sprinkler holes?

39. assignment (electric force)

Assignment text: Four charges (-5 microcoulombs, 5 microcoulombs, 5 microcoulombs, 10 microcoulombs) are located on the corners of a rectangle as shown in figure. The dimensions of the rectangle are L=60 cm W=15 cm. Calculate the magnitude and direction of the total electric force exerted on the charge at the lower left corner by the other three charges.

40. assignment (inelastic collision)

Assignment text: Two cars approach an intersection at a right angle to each other. If an inelastic collision occurs at the intersection, determine the x component of the final momentum of the combined vehicles. Car1 of mass 1,117.38 kg approaches the intersection from the left with a speed of 22.53 m/s. Car 2 of mass 1,195.19 kg approaches the intersection from the south with a speed of 16.27 m/s.

41. assignments (magnetic force)

Assignment text: An electron moves with a speed of 3.5×107m/s in the directions shown in (Figure 1) below. A 0.60T magnetic field points in the positive x-direction. Part A What is the magnitude of the magnetic force in figure (a)? Express your answer with the appropriate units. Part B What is the direction of the magnetic force in the figure (a)? Part C What is the magnitude of the magnetic force in figure (b)? Express your answer with the appropriate units. Part D What is the direction of the magnetic force in the figure (b)?

42. assignments (wave speed)

Assignment text: Calculate the speed of the wave whose representation in SI units is Ψ(z,t)=A cos(1*10^6 z + 8.2*10^14 t) Give your answer in m/s.

43. assignments (orbit)

Assignment text: How much energy would be required to move the Moon from its present orbit around Earth to a location that is six times as far away? Assume the Moon's orbit around Earth is nearly circular and has a radius of 3.84 ?*10^8 m, and that the Moon's orbital period is 27.3 days.

44. assignment (diffraction grating)

Assignment text: Which one of the following actions would make the maxima in the interference pattern from a grating move closer together? a Increasing the number of lines per length. b Increasing the distance to the screen. c Increasing the frequency of the laser. d Decreasing the frequency of the laser.

45. assignment (mass percentage)

Assignment text: 1. Find the percentage by mass of Cl in MgCl2? 2. What is the percentage by mass of sodium (Na) in salt, NaCl?

46. assignment (heat capacity)

Assignment text: A block of material has a mass of 163 kg and a volume of 5.45 x 10-2 m3. The material has a specific heat capacity and coefficient of volume expansion, respectively, of 848 J/(kg C°) and 5.32 x 10-5 (C°)-1.

47. assignment (magnetic force)

Assignment text: A 4.55m long wire is put into a magnetic field of 0.0600T. The angle between the wire and the magnetic field is adjusted to be 90 degrees. How much current is flowing in the wire if the magnetic force on it is 0.625N? Express your answer to three significant figures and include the appropriate units.

48. assignment (rms speed)

Assignment text: 1) Find the rms speed and the average kinetic energy of a hydrogen atom at a temperature of 1.7 x 107K. (At this temperature, which is of the order of the temperature in the interior of a star, the hydrogen is ionized and consists of a single proton.) m/s 2)J

49. assignment (mass of the electron)

Assignment text: Find the mass of an electron when the specific charge for the electron is 2.083 x 10 11 C/kg

50. assignment (electric circuit)

Assignment text: The circuit in the figure below has a battery of 33.0 V and the following resistors: R1=4.00 Ω, R2=5.00 Ω, R3=8.00 Ω, R4=8.00 Ω, R5=11.00 Ω. a. Find the equivalent resistance. b. Find the voltage drop across R3. c. Fin the power dissipated in R3. d. Find the power supplied by the battery.

51. assignment (simple pendulum)

Assignment text: The earth's acceleration due to gravity varies from 9.780 m/s2at the equator to 9.832 m/s2 at the poles. A pendulum whose length is precisely 1.000 m can be used to measure g. Such a device is called a gravimeter. How long do 100 oscillations take at the equator? How long do 100 oscillations take at the north pole?

52. assignment (interference)

Assignment text: Two sources of coherent radio waves broadcasting in phase are located as shown below.(Figure 1) Each grid square is 0.5 m square, and the radio sources broadcast at ?=2.0m. Part A At Point A is the interference between the two sources constructive or destructive? Part B At Point B is the interference between the two sources constructive or destructive? Part C At Point C is the interference between the two sources constructive or destructive? Part D At Point D is the interference between the two sources constructive or destructive?

53. assignment (inelastic collision)

A manufacturer of barriers for racing circuits is testing the impact absorption capabilities of its new product. A 1000 kg (mb) barrier of the new material is installed in a test room and the friction coefficient of the barrier with the floor is μb = 0.8. A 100 kg (ms) steel block (considered infinitely rigid in comparison with the barrier) is accelerated by a hydraulic system which applies a constant force Fh = 1 kN for a time t1 of 3 seconds before releasing the block. The steel block slides on the floor with a friction coefficient of μs = 0.1. After a rectilinear motion for a distance Δx2 = 2 m (still on the same floor) the steel block hits the barrier. At the end of the test the engineers find that the barrier has moved by Δxb = 10 cm. B. Now much energy is lost in friction before the impact? 1. Find the kinetic energy of the block ms, just before release. 2. Find the energy transmitted to the block mb.

54. assignment (heating coil)

Assignment text: A portion of Nichrome wire of radius 2.70 mm is to be used in winding a heating coil. If the coil must draw a current of 8.70 A when a voltage of 120 V is applied across its ends, find the following. (Take the resistivity of nichrome to be 1.50 10-6 ohm · m.) (a) the required resistance of the coil 1 ohm (b) the length of wire you must use to wind the coil 2 m

55. assignments (wave in a string)

Assignment text A wave in a string is described by the equation y(x,t) = 0.241 sin{2 (x/24.4 – t/0.326)} where all length quantities are in centimeters and time quantities are in seconds. What is the average speed (in cm/s) of a point on the rope during one complete oscillation of the string?

56. assignment (electric levitation)

Assignment text: A Styrofoam ball covered with a conducting paint has a mass of 4.3*10^-3 kg and has a charge of 3.6 microcoulombs. What electric field directed upward will produce an electric force on the ball that will balance its weight?

57. assignment (speed of sound)

Assignment text: A mirror faces a cliff located some distance away. Mounted on the cliff is a second mirror, directly opposite the first mirror and facing toward it. A gun is fired very close to the first mirror. The speed of sound is 374 m/s. How many times does the flash of the gunshot travel the round-trip distance between the mirrors before the echo of the gunshot is heard? N =

58. assignment (ray optics)

Assignment text: Suppose the image of an object is upright and magnified 2.00 times when the object is placed 20.0 cm from a particular converging lens. (a) Find the location of the image. q = cm (b) Find the focal length of the lens. f = cm

59. assignments (induced emf)

Assignment text: A circular loop in the plane of the paper lies in a 0.34T magnetic field pointing into the paper. If the loop's diameter changes from 20.0cm to 6.6cm in 0.40s. What is the magnitude of the average induced emf?

60. assignment (parallel plate capacitor)

Assignment text: A non-linear capacitive displacement sensor is constructed using three plates; two fixed and one moveable. Each plate is "y" width and "L" length. The fixed once are separated by a distance "d" as shown below. Assuming that you can measure the capacitance of the total device, derive an expression giving the distance x1 and x2 in terms of the measured capacitance C. Also assume the permittivity of the dielectric materials between the top two plates is el and the bottom two plates is e2. Hint: For Capacitors in series C=C1C2/(C1+C2)

61. assignments (capacitors)

A 2.29 microF capacitor and a 6.33 microF capacitor are connected in series across a 23.0 V battery. What voltage would be required to charge a parallel combination of the same two capacitors to the same total energy?

62. assignment (kinematics)

Assignment text: An inquisitive physics student and mountain climber climbs a 47.0-m-high cliff that overhangs a calm pool of water. He throws two stones vertically downward, 1.00 s apart, and observes that they cause a single splash. The first stone has an initial speed of 2.12 m/s. (a) How long after release of the first stone do the two stones hit the water? (b) What initial velocity must the second stone have if the two stones are to hit the water simultaneously? magnitude = (c) What is the speed of each stone at the instant the two stones hit the water? first stone = second stone =

63. assignment (average kinetic energy)

Assignment text: What's the average kinetic energy per molecule in helium at 308K ? What's the average kinetic energy per molecule in nitrogen at 308K ?

64. assignment (breathing)

What outward force is needed on the outside of a lung to create the pressure P noted in Figure 10.33, where P = -6.00 mm Hg? Take the area affected to be 320 cm2. (This force is easily created by the diaphragm and chest muscles, as we breathe many times a day.)

65. assignment (linear impulse)

Assignment text: If the 150 lb (68.0389 kg) crate is released from rest at point A, determine its speed after it slides 30 feet (9.144 m) down the plane. The coeffecient of kinetic friction between the crate is uk = 0.3.

66. assignment (relativistic velocity addition)

Assignment text: Two electrons move in opposite directions each with a speed of 0.7c as measured in the laboratory. The speed one electron measures for the speed of the other electron is: a. 0.25c b. 0.70c c. 0.94c d. 0.98c e. 0.99c

67. assignment (energy level)

Assignment text: -0.3 eV (third excited state) -1.0 eV (second excited state) -2.4 eV (first excited state) -4.7 eV (ground state) (a) Suppose that material containing many such objects is hit with a beam of energetic electrons that ensures that there are always some objects in all of these states. What are the six energies of photons that could be strongly emitted by the material? (In actual quantum objects there are often "selection rules" that forbid certain emissions even though there is enough energy; assume that there are no such restrictions here.) List the photon emission energies in order from largest to smallest. If two different transitions would produce photons of the same energy, list that energy twice:

68. assignment (pressure in the spinal fluid)

Assignment text: Figure 10.36. Pressure in the spinal fluid is measured as shown in Figure 10.36. Assume that the pressure P in the spinal fluid is 10.8 mm Hg. (a) What is the reading of the water manometer in cm water? cm H2O (b) What is the reading if the person sits up, placing the top of the fluid 55.0 cm above the tap? The fluid density is 1.05 g/cm3. cm H2O

69. assignment (linear accelerator)

Assignment text: A helium nucleus (charge +2e) moves through a potential difference deltaV= -0.700 kV . It's initial kinetic energy is 2.60 x 10^16 J. What is it's final kinetic energy?

70. assignments (magnetic field)

Assignment text: As shown in the figure below, two long parallel wires (1 and 2) carry currents of I1 = 2.94 A and I2 = 4.55 A in the direction indicated.

71. assignment (frictional force)

Assignment text: Suppose you have a 105-kg wooden crate resting on a wood floor. The coefficients of static and kinetic friction here are s=0.5 and k=0.3. m = 105 kg

72. assignment (force in the knee joint)

Assignment text: During strenuous exercise it is possible to exert forces to the joints that are ten times greater than the weight being supported when not in motion. The coefficients of friction for joints are generally very small - for this problem, assume the coefficient of static friction in a knee joint is 0.016, while for kinetic friction it is 0.015. m = 69 kg (A) What is the frictional force in the knee joint of a person who is standing still and supporting 69 kg of her mass on a knee? (B) What is the maximum force of friction if this person begins strenuous exercise?

73. assignment (energy in the inductor)

Assignment text: At a given instant the current through an inductor is 24.5 mA and is increasing at the rate of 135mA/s. How long does it take for the energy to increase by a factor of 8 from the initial value?

74. assignment (light refraction)

Assignment text: As you may have learned when studying the properties of thermal energy, building contractors often install double-glazed windows to prevent thermal energy ("heat") from entering/exiting the building. Although effective as insulators, such windows present interesting optical effects. In the figure, a double-glazed window comprises two identical panes of glass (ng = 1.54) separated by an air gap. If the light encounters the glass at an angle of 40.00° with respect to the glass, find the shift in path (delta x) as the light enters the room. (Use n air = 1.00)

75. assignment (linear momentum)

Assignment text: Provide all logical steps in the solution(s)/ answer(s). A child of mass 28.0 kg is sliding on ice with a velocity of 2.25 m/s in the positive x direction. She is holding a 2.4 kg ball in her hand. She throws the ball straight ahead of her with a velocity of 2.70 m/s (in the + x direction.) a. What is her velocity immediately after releasing the ball? (b) What is the velocity of the center of mass of the child and ball immediately after she releases the ball? (If you don't do a calculation you must give a logical explanation for your answer.)

76. assignment (light refraction)

Assignment text: You've dropped your car keys at night off the end of a dock into water 1.6 m deep. A flashlight held directly above the dock edge and 0.50 m above the water illuminates the keys when it's pointed at 400 to the vertical, as shown in the figure. (Figure 1)

77. assignment (force)

Assignment text: At some point during their orbit, the location of the Earth and Moon relative to the Sun will be as shown in the figure below. What are the magnitude and direction of the force experienced by the Moon due to the Sun and the Earth? (The mass of the Moon is 7.35*10^22 kg, the Earth has a mass 5.97*10^24 kg, and the Sun has a mass 2.00*10^30kg. In the figure, the distance from the Moon to the Earth is 3.84*10^8 m and the distance from the Moon to the Sun is 1.50*10^11 m.)

78. assignment (ray optics)

Assignment text: In the 7 diagrams below, the solid arrow represents the object and the dashed arrow the image. The rectangle shows the position of an SINGLE OPTICAL ELEMENT. Match each diagram with the appropriate optical element.

79. assignment (stress)

Assignment text: A marble column of cross-sectional area 0.50m^2 supports a mass of 26000kg . 1.) What is the stress within the column? 2.) What is the strain? Use E marble=5.0×10^10 N/m^2.

80. assignment (voltage)

Assignment text: Consider point a which is 70 cm north of a -4.4 µC point charge, and point b which is 84 cm west of the charge .

81. assignment (magnetic field)

Assignment text: Suppose that in Fig. 19.23, I1 = 0.5 A, I2 = 3.3 A, and I3 = 1.9 A. What is the magnitude of the B-field at a radial distance from the wire of 1.20 m?

82. assignment (incoherent light source)

Assignment text: If I were to take an incoherent light source such as lamp and measured the incoming light at a given point in space some distance from that lamp, surely, the number of light waves at the minimum point on their oscillation and the number of light waves at the maximum point on their oscillation would be equal. And so, would we not expect them to interfere destructively giving a net effect of zero light, or close to zero light? What I am trying to say is if the lamp emits lots of random beams of light won't they all just cancel giving a net effect of zero? Clearly, the lamp still appears bright so where does this logic fall down?

83. assignment (half-life)

Assignment text: One gram of radioactive material with an atomic number 202 has an activity of 1.2 Ci. Determine its half-life in years. (1 Ci stands for one Curie which represents 3.7*10^10 disintegrations per second.)

84. assignment (elastic energy)

Assignment text: A 1.7-kg mass is attached to a spring with a force constant of 59 N/m. If the mass is released with a speed of 0.21 m/s at a distance of 7.2 cm from the equilibrium position of the spring, what is its speed when it is halfway to the equilibrium position? _______ m/s

85. assignment (almost ballistic pendulum)

Assignment text: . A bullet of mass m and initial velocity vo, passes through a block of mass M suspended by an unstretchable, massless string of length L from an overhead support. It emerges from the collision on the far side traveling at v1 less than vo. This happens extremely quickly (before the block has time to swing up) and the mass of the block is unchanged by the passage of the bullet (the mass removed making the hole is negligible, in other words). After the collision, the block swings up to a maximum angle (Theta max) and then stops. Find (Theta max).

86. assignment (Lorentz force)

Assignment text: An electron in a cathode-ray tube is accelerated through a potential difference of 10 kV, then passes through the d = 1.5-cm-wide region of uniform magnetic field in the figure (Figure 1) . What field strength will deflect the electron by  = 11 degrees?

87. assignment (conservation of angular momentum)

Assignment text: A physics student is sitting on a frictionless platform that is rotating with an angular speed of wi = 2.8 rad/s. His arms are outstretched, and he is holding a heavy weight in each hand. The moment of inertia of the student, the extended weights, and the platform about the rotation axis is Ii = 12.5 kg*m2. When the student pulls the weights inward toward his body, the moment of inertia decreases to If = 5.7 kg*m2.

88. assignment (wave pulse)

Assignment text: . Figure 1 depicts two wave pulse A and B. each traveling at a speed of 5 m/s heading toward one another along a string. Draw the wave shape (a) 2 s later (b) Again 2 s after that.

89. assignment (angular resolution)

Assignment text: The Earth and Moon are separated by about 400x106 m. suppose Mars is 2.9 1011 m from Earth and forms a right triangle with Earth and the Moon. Assume a pupil diameter of 6 mm and l= 550 nm. Determine the following. Could a person standing on Mars resolve the Earth and its Moon as two separate objects without a telescope? Angular separation of Earth and Moon as seen from Mars: Angular resolution of the eye:

90. assignment (conservation of angular momentum)

Assignment text: A figure skater during her finale can increase her rotation rate from an initial rate of 1.12 revolutions every 2.00s to a final rate of 3.09 revolutions per second. If her initial moment of inertia was 4.45kg*m2, what is her final moment of inertia?

91. assignment (solenoid magnetic field)

Assignment text: You have a 500mm long solenoid, with 1000 turns, and a diameter of 8mm. a) If a steady current I goes through the wire, approximately what is the magnetic field inside? b) When the current is I, find the approximate magnetic flux. c) Find the self inductance of the solenoid. d) The solenoid is placed upright, and hooked up to a circuit that makes the current flow upwards. A voltmeter is hooked up (in series) with the solenoid and shows that the top of the solenoid is at a steady higher "voltage". Is the current increasing, decreasing, or holding steady?

92. assignment (collision)

Assignment text: A 4 kg mass moving along the x-axis at +2 m/s collides elastically head-on with 3 kg mass moving at -3 m/s along the x-axis. Determine the final velocity of each mass after the Frictionless surface collision.

93. assignment (power line)

Assignment text: A 18km long, 230 kV aluminum transmission line delivers 33MW to a city. a. If we assume a solid cylindrical cable, what minimum diameter is needed if the voltage decrease along this run is to be no more than 1.0 % of the transmission voltage? The resistivity of aluminum is 2.7×10-8 Ω m.

94. assignment (velocity addition)

Assignment text: Consider a pool game being played on a pool table on the deck of an aircraft carrier near the bow (front). Assume that the carrier is moving north at 25.0 m/s. As a result of the initial break, a ball flies over the edge of the table and over the edge of the deck with a horizontal component of velocity directed toward the bow of the ship of 5.00 m/s. What is vbw, the horizontal component of the speed with which this ball strikes the water in front of the ship (i.e., what is the speed of the ball relative to the water)? Express your answer numerically in meters per second. Use ordinary (Galilean) physics

95. assignment (sound frequency)

Assignment text: If sound travels at a speed of 345 m/s, what is the frequency (in hertz) of a wave with a wavelength of 0.6 meters?

96. assignment (inelastic collision)

A 110 kg tackler moving at 2.5 m/s meets head-on (and holds on to) an 82 kg halfback at 5.0 m/s. What will be their mutual speed immediately after the collision?

97. assignment (rest mass)

Assignment text: What is the speed of an electron (in c unit) that has been accelerated to the point at which its mass is 2.4 times its rest mass? The rest mass of an electron is 9.11 ×10-31kg.

98. assignment (kinematics)

Assignment text: Pool players often pride themselves on their ability to impart a large speed to a pool ball. In the sport of billiards, event organizers often remove one of the rails on a pool table to allow players to measure the speed of their break shots (the opening shot of a game in which the player strikes a ball with his pool cue). With the rail removed, a ball can fly off the table. As the only participant with a physics background, they have placed you in charge of determining the speed of the players' break shots. The top of the pool table is 0.850 m from the floor. The placement of the tape is such that 0 m is aligned with the edge of the table (as shown). The winner of the competition wants to know if he has broken the world record for the break shot of 32 mph (about 14.3 m/s). If the winner's ball landed a distance 4.05 m from the table edge, calculate his break shot speed. At what speed did his pool ball hit the ground?

99. assignment (evaporation)

Assignment text: So here is the thing, I searched all over the internet for this but all the sources say that I need wind because the process of evaporation goes as follow: Water particles at the top layer with highest levels of energy (which they take from lower layers) are trying to break free and jump up. When they meet air particles with enough energy, they take that energy and use it to break the bonds with the other liquid- thus escaping and turning into a gas. Now my question is, what if I got no wind? What if instead I just put a heating coil close to the surface of the liquid which is in a barrel (i.e not touching the water)? Would my liquid just boil? Or maybe the energy from the coil would transfer to top layer first, giving it enough energy to escape (and cool the rest of the liquid)? What if the barrel closed? What if it is open? All of the internet sources say that I have to have air movement, does this mean that my scenario won't work? Also, if it would, does that mean that the energy required to make the water dissapear with evaporation is lower than with boling?

100. assignment (periodic motion)

Assignment text: An air track glider with a mass of 0.4 kg is attached to a spring with a spring constant of 0.1 N/m. The glider bounces back and forth from the 0.75-meter mark to the 1.25-meter mark. What is the amplitude for this motion? Answer in meter

101. assignment (Earth's magnetic field motor)

Assignment text: People have proposed driving motors with the earth's magnetic field. This is possible in principle, but the small field means that unrealistically large currents are needed to produce noticeable torques. Suppose a 17-cm-diameter loop of wire is oriented for maximum torque in the earth's field. What current would it need to carry in order to experience a very modest 1.0×10^3 Nm torque?

102. assignment (magnetic force on a wire)

Assignment text: Two parallel wires are orientated perpendicular to the page as shown in figure Q20.9. The wires carry equal currents, and the direction of the current is into the page for each. The vertices of an equilateral triangle are marked by the two wires and a point P as shown. (a) What is the direction of the magnetic field produced by the two wires at point P? (b) A third wire, parallel to the other two and carrying the same current in the same direction, is placed at point P. Determine the direction of the force on the wire at this point.

103. assignment (photon energy)

Assignment text: The dissociation energy of a molecule is the energy required to break apart the molecule into its separate atoms. The dissociation energy for a particular molecule is 1.17 × 10-18 J. Suppose that this energy is provided by a single photon. Determine the (a) wavelength and (b) frequency of the photon. (c) In what region of the electromagnetic spectrum does this photon lie?

104. assignment (refractive index)

Assignment text: Based on your data, what is the average speed of light in your prism? Data: Alpha = 56 degrees Delta m = 40 degrees

105. assignment (capacitor)

Assignment text: It is desired that 9.5 μC (microcoulombs) of charge be stored on each plate of a 3.5 μF (microfarads) capacitor. What potential difference is required between the plates?

106. assignment (acceleration)

Assignment text: A car accelerated from 5.3 mph (0.44704 m / s) to some final velocity over 9.0 s. Then, for the next 20.5 s the car was driving at this final velocity. The total distance traveled by the car over the entire time turned out to be 347.8 m. What was acceleration of the car over the first 9.0 s?

107. assignment (wave frequency)

Assignment text: A sound wave of the form s=sm*cos(k*x-omega*t + phi) travels at 345 m/s through air in a long horizontal tube. At one instant, air molecule A at x=2.01 m is at its maximum positive displacement of 6.00 nm and air molecule B at x=2.11 m is at a positive displacement of 2.40 nm. All the molecules between A and B are at intermediate displacements. What is the frequency of the wave?

108. assignment (kinetic theory of gases)

Assignment text: 1 L of oxygen gas has a temperature of 0°C and a pressure of 1 atm. What is the total translational kinetic energy of the molecules of oxygen gas?

109. assignment (tensile force)

Assignment text: A steel cable with cross-sectional area 3.50cm2has an elastic limit of e0=2.40×108Pa. Part A Find the maximum upward acceleration that can be given an elevator of mass 1160kg supported by the cable if the stress is not to exceed one-third of the elastic limit.

110. assignment (rope - centripetal force)

Assignment text: A bucket of mass 1.00 kg is whirled in a vertical circle of radius 1.40 m. At the lowest point of its motion the tension in the rope supporting the bucket is 25.0 N. (a) Find the speed of the bucket. (b) How fast must the bucket move at the top of the circle so that the rope does not go slack?

111. assignment (double slit experiment)

Assignment text: In a double-slit experiment it is found that blue light of wavelength 453nm gives a second-order maximum at a certain location on the screen. Q:What wavelength of visible light would have a minimum at the same location?

112. assignment (converging lens - ray diagram)

Assignment text: Part A Using a converging lens that has focal length f=500mm, How far behind the lens do you expect to see a sharp image of an object located 5.00 m in front of the lens? Express your answer with the appropriate units.

113. assignment (escape speed)

Assignment text: What is the escape speed from the sun, beginning (from rest relative to the sun) at the orbit of Earth, R = 1.50 10^8 km. (Given: G = 6.67 ´10^–11 N · m^2/kg^2; mass of the sun = 2.0 *10^30 kg.)

114. assignment (soap film - diffraction)

Assignment text: A soap film made with material of index of refraction n=1.9 is illuminated by white light. If the reflected light is maximum at lambda=350 nm, what is the minimum thickness the film could have had?

115. assignment (diffraction grating in astrophysics)

Assignment text: An application of spectra produced by a diffraction grating is in astrophysics, where the Doppler shift of a particular galaxy can be measured to determine the velocity of the galaxy with respect to us. If the red hydrogen line in the galaxy's spectrum is observed at 674 nm instead of 658 nm, first think about whether that means the galaxy is moving toward us or away from us. Then, recalling that the Doppler equation for electromagnetic waves states that the magnitude of the shift in frequency associated with relative motion between a source and observer is |f ' - f | = vf/c, where f ' is the observed frequency and f is the frequency emitted by a stationary source, determine v, the relative speed of the galaxy with respect to us. Take the speed of light to be 3.00 x 10^8 m/s. State the galaxy's velocity with respect to us, including a plus sign if the velocity Is directed away from us, and a minus sign if It is directed toward us. Note that the Doppler equation is valid as long as the speed is not too close (10% of c or higher) to the speed of light, and we can get away with applying it here.

116. assignment (work function)

Assignment text: A sample of potassium metal (in a vacuum) is illuminated by a light source as shown above. The photoelectrons (i.e. electrons emitted from the potassium when exposed to light) are collected on plate P, and the electron current is measured by the meter G. The work function of potassium is 2.0 eV. a) Initially red light (700 nm) is shown on the metal, but the wavelength of the light is slowly decreased. At what wavelength should a person first read a current on the meter? b) As the wavelength is decreased until the light is violet (400 nm) will the current continue to increase? Assume that the intensity of the light stays constant as you decrease its wavelength. c) Find the kinetic energy and the speed of the electrons emitted when the light source is at 400 nm.

117. assignment (fluid density)

Assignment text: A rectangular gasoline tank can hold 50.0 kg of gasoline when full. What is the depth of the tank if it is 0.500 m wide by 0.900 m long? What is the volume of the tank? (It is suitable for a passenger car.)

118. assignment (buoyancy - spherical shell of copper)

Assignment text: A spherical shell of copper with an outer diameter of 12 cm floats on water with 60% of its volume above the water’s surface. Find the inner diameter of the shell. The density of copper is 8930 kg/m3. Answer in units of cm.

119. assignment (solenoid - magnetic field)

Assignment text: An ideal solenoid having a coil density of 5000 turns per meter is 10 cm long and carries a current of 4.0 A. What is the strength of the magnetic field at its center? A) 25mT B) 13mT C) 3.1mT D) 6.2mT

120. assignment (solenoid - magnetic field)

Assignment text: A long solenoid that has 1,040 turns uniformly distributed over a length of 0.355 m produces a magnetic field of magnitude 1.00 10-4 T at its center. What current is required in the windings for that to occur? mA

121. assignment (coefficient of static friction - ladder)

Assignment text: A uniform ladder 5.00 m long weighing 300 N rests against a vertical frictionless wall with its lower end 3.00 m from the wall. A man weighing 700 N climbs slowly up the ladder and it starts to slip when he has climbed 2.00 m along the ladder. Find the coefficient of static friction between the ladder and the floor.

122. assignment (electrostatic force)

Assignment text: 1. the particles have charges q1 = -q2 = 266 nC and q3 = -q4 = 104 nC, and distance a = 4.0 cm. what is the x and y component of the net electrostatic force on particle 3?

123. assignment (kinetic energy - skier)

Assignment text: A skier skis from rest from vertical height h1=19.6 m over two successively lower hills of vertical height h2=15 m and h3=8.8 m . The summit of the third hill fits a circle of radius h3 centered at height 0 m. Friction with snow and air resistance is negligible. a) Find her speeds at x1, x2, x3 b) Does the skier leave the surface at x3? If not what should h1 be so that she just leaves the surface at x3? If yes find the maximum value of h1 at which the skier stays on. (Ignore the middle hill in this calculation.)

124. assignment (kinetic energy - spring)

Assignment text: 2) A mass pushed by a spring. You have an object, m = 0.20 kg, compressing a spring, spring constant K = 26 N/m. You release the spring and the object leaves the spring system with a kinetic energy of 10 Joules. For this problem ignore air drag. Assuming the total energy is constant: a) Find the initial compression of the spring, x. b) Find the compression of the spring when the kinetic energy is 2.5 Joules. c) Find the speed when the kinetic energy is 2.5 Joules.

125. assignment (capacitor reactance)

Assignment text: A. What is the reactance of a 2.70 µF capacitor at a frequency of 50.0Hz B. What is the reactance of a 2.70 µF capacitor at a frequency of 3.30MHz

126. assignment (inertial force)

Assignment text: Two blocks, stacked one on top of the other, can move without friction on a horizontal surface, where M = 5.6 kg. The surface between the two blocks is rough, however, with a coefficient of static friction equal to 0.48. (a) If a horizontal force F is applied to the 5.6-kg bottom block, what is the maximum value F can have before the 2.0-kg top block begins to slip? (b) If the mass of the top block is increased, does the maximum value of F increase, decrease, or stay the same? Explain.

127. assignment (wave equation)

Assignment text: What is the amplitude of this wave? What is the wavelength of this wave? What is the frequency of this wave?

128. assignment (gas equation)

Assignment text: 1. A 0.110 m^3 helium gas tank is at 160 atm. How many spherical balloons can be inflated to 1.20 atm using the gas tank if the balloons have 0.150 m radius at 1.230 atm?

129. assignment (forces in vertical motion)

Assignment text: a. With barbell at rest both forces are equal b. With barbell moving upward forces are equal c. With barbell moving downward forces are equal

130. assignment (telescope)

Assignment text: The objective lens of a telescope is a symmetric glass lens with 150cm radii of curvature. The eyepiece lens is also a symmetric glass lens. Part A: What are the radii of curvature of the eyepiece lens if the telescope's magnification is 20×?

131. assignment (torque equilibrium)

Assignment text: A 44-N crate is suspended from the left end of a plank. The plank weighs 21 N, but it is not uniform, so its center of gravity does not lie halfway between the two ends. The system is balanced by a support that is 0.30 m from the left end of the plank. How far to the right of the support is the plank's center of gravity?

132. assignment (horizontal oscillation - mass on a spring)

Assignment text: A 21.0kg block at rest on a horizontal frictionless air track is connected to the wall via a spring. The equilibrium position of the mass is defined to be at x=0. Somebody pushes the mass to the position x= 0.350m, then lets go. The mass undergoes simple harmonic motion with a period of 3.50s. What is the position of the mass 2.905s after the mass is released? b) Consider the same mass and spring discussed in the previous problem. What is the magnitude of the maximum acceleration the mass undergoes during its motion?

133. assignment (thermal expansion - rivets)

Assignment text: 1. Aluminum rivets used in airplane construction are made slightly too large for the rivet holes to be sure of a tight fit. The rivets are cooled with dry ice (-78.5° C) before they are driven into the holes. If the holes have a diameter of 0.6400 cm at 20.9° C, what should be the diameter of the rivets at 20.5° C if they are to just fit when cooled to the temperature of dry ice?

134. assignment (vertical oscillation - free pebble on a block )

Assignment text: A 0.113-kg block is suspended from a spring. When a small pebble of mass 27 g is placed on the block, the spring stretches an additional 5.5 cm. With the pebble on the block, the block oscillates with an amplitude of 13 cm. Find the maximum amplitude of oscillation at which the pebble will remain in contact with the block. There is no diagram for this problem. I just have no idea where to start. Do you use conservation of energy theorem to solve?

135. assignment (relativistic motion)

Assignment text: At what speed v will the length of a 1.00m stick look 13.5 cm shorter (86.5cm )? v = ........ c A proton is traveling in an accelerator with a speed of 1.3×108m/s .By what factor does the proton's kinetic energy increase if its speed is doubled?

136. assignment (electron in a box)

Assignment text: An electron confined to a box has an energyof 1.63eV . Another electron confined to an identical box has an energy of 3.67eV . What is the smallest possible length for those boxes? L=?

137. assignment (light refraction - rad and violet)

Assignment text: A beam of light containing red (660 nm) and violet (410 nm) wavelengths travels from air, through a flat piece of crown glass 2.88 cm thick, and then back to air. (a) If the beam has an angle of incidence of 45.0° in air, determine the angle at which the two colors of light emerge from the crown glass. The index of refraction respectively for red and violet light in crown glass is 1.512 and 1.530. (Enter a number to three decimal places.)

138. assignment (RC circuit)

Assignment text: A simple RC circuit is shown below, where R=2.50 megaohms and C=1.50 microfarads. The capacitor has a charge of 90 microcoulombs before the switch is closed. The switch closes at 0s. a) determine the time constant of the circuit b) determine the charge on the capacitor 3.00 s after the switch closes c) determine the time when the current through the resistor is 6.50 microamperes

139. assignment (relativistic kinetic energy)

Assignment text: calculate the kinetic energy of an electron moving at 0.883c. Express your answer in keV. A.750keV B.490keV C.660keV D.580keV

140. assignment (mechanical energy - orbiter)

Assignment text: Ten days after it was launched toward Mars in December 1998, the Mars Climate Orbiter spacecraft (mass 629 kg) was 2.87×106km from the Earth and traveling at 1.20×104km/h relative to the Earth. a) At this time, what was the spacecraft's kinetic energy relative to the Earth? b) What was the potential energy of the earth-spacecraft system?

141. assignment (photon wavelength)

Assignment text: find the wavelength (in nm) of a 8.69 eV photon. A.157nm B.121nm C.143nm D.170nm

142. assignment (AC circuit)

Assignment text: Consider the AC circuit in the figure. The frequency of the AC source is adjusted while its voltage amplitude is held constant. The lightbulb will glow the brightest at which of the following? - high frequencies - the brightness will be same at all frequencies - low frequencies

143. assignment (electric circuit - currents)

Assignment text: In fig. 27-70, the ideal battery has emf e=30.0 V, and the resistances are R1=R2=14 ohms, R3=R4=R5=6.0 ohms, R6=2.0 ohms, and R7=1.5 ohms. What are currents (a)i2 (b)i4 (c)i1 (d)i3 (e)i5

144. assignment (simple pendulum)

Assignment text: A man enters a tall tower, needing to know its height. He notes that a long pendulum extends from the ceiling almost to the floor and that its period is 17.0s. a. How tall is the tower? in meters b. If this pendulum is taken to the moon, where the free-fall acceleration is 1.67 m/s2, what is the period there? in seconds

145. assignment (relativistic kinetic energy - meson)

Assignment text: What is the kinetic energy in MeV of a ?–meson that lives 1.50×10-16 s as measured in the laboratory, and 0.840×10-16 s when at rest relative to an observer, given that its rest energy is 135 MeV?

146. assignment (relativistic motion - muon)

Assignment text: Suppose a muon produced as a result of a cosmic ray colliding with a nucleus in the upper atmosphere has a velocity v = 0.9500c. Suppose it travels at constant velocity and lives 1.52 µs as measured by an observer who moves with it (this is the time on the muon's internal clock). It can be shown that it lives for 4.87 µs as measured by an earth-bound observer (see Example 26.1 in the textbook). Give all answers correct to 4 significant figures. (a) How long would the muon have lived as observed on earth if its velocity was 0.0700c? (b) How far would it have traveled as observed on earth? (c) What distance is this in the muon's frame?

147. assignment (refraction and reflection)

Assignment text: If n1 less-than n2 and n3 less-than n2, which of the following statements are true when it comes to finding out if you have destructive interference of the reflected rays? You do need to know if n1 is bigger or smaller than n3. You cannot make any calculations unless you know the numerical value of n3. You cannot make any calculations unless you know the numerical value of n2. The reflected ray from the interface between medium 1 and medium 2 will undergo a different phase change than the ray reflected from the interface between 2 and 3. You cannot make any calculations unless you know the numerical value of the thickness of layer 2. You cannot make any calculations unless you know the numerical value of n1.

148. assignment (refraction - soap)

Assignment text: a) What is in nm the smallest thicknesses of a soap bobble that produce constructive interference upon reflection for light with a wavelength of 383 nm? Use 1.333 for the index of refraction of soap. b) What is in nm the second smallest thicknesses of a soap bobble that produce constructive interference upon reflection? c) What is in nm the smallest thicknesses of a soap bobble that produce destructive interference upon reflection for the same light? d) What is in nm the second smallest thicknesses of a soap bobble that produce destructive interference upon reflection for the same light?

149. assignment (angular acceleration )

Assignment text: The combination of an applied force and frictional force produces a constant total torque of 34.2 Nm on a wheel rotating about a fixed axis. The applied force acts for 6.3s during which time, the angular speed of the wheel increases for 1.60 rad/s to 12.20 rad/s. The applied force is then removed. The wheel comes to rest in 66.4s a.) what is the rad/s^2 the angular acceleration of the wheel before the applied force is removed? b.) what is in kg m^2 the moment of interia of the wheel? c.) what is in rad/s^2 the angular acceleration of the wheel after the applied force is removed? d.) what is in N m the torque due to friction (after the force is removed)?

150. assignment (buoyant force)

Assignment text: a) Calculate the buoyant force on a 2.60 L helium balloon. N (upward) I calculated it to be 0.0329 N (b) Given the mass of the rubber in the balloon is 1.90 g, what is the net vertical force on the balloon if it is let go?

151. assignment (nuclear fission)

Assignment text: The radium isotope 223Ra, an alpha emitter, has a half-life of 11.43 days. You happen to have a 1.1g cube of 223Ra, so you decide to use it to boil water for tea. You fill a well-insulated container with 200mL of water at 18 0C and drop in the cube of radium. How long will it take the water to boil?

152. assignment (Law of Malus)

Assignment text: The average intensity of light emerging from a polarizing sheet is 0.642 W/m2, and that of the horizontally polarized light incident on the sheet is 0.971 W/m2. Determine the angle that the transmission axis of the polarizing sheet makes with the horizontal.

153. assignment (Law of Malus)

Assignment text: Before attempting this problem, review Conceptual Example 8. The intensity of the light that reaches the photocell in the drawing is 160 W/m2, when θ = 20°. What would be the intensity reaching the photocell if the analyzer were removed from the setup, everything else remaining the same?

154. assignment (eye lens)

Assignment text: A student is reading a lecture written on a blackboard. The lenses in her eyes have a refractive power of 67.70 diopters, and the lens-to-retina distance is 1.483 cm. (a) How far (in meters) is the blackboard from her eyes? m (b) If the writing on the blackboard is 4.20 cm high, what is the size of the image on her retina (including the proper algebraic sign)? cm

155. assignment (atomic energy level)

Assignment text: Consider a pretend atom whose electrons can have any of these Energies: (Level) Energy : A -14eV B -5eV C -9eV D -2eV For each transition below, choose whether it must emit or absorb a photon: A ? B must D ? C must C ? B must

156. assignment (conservation of angular momentum)

Assignment text: A large wooden turntable in the shape of a flat uniform disk has a radius of 2.00 m and a total mass of 120 kg. The turntable is initially rotating at 3.00 rad/s about a vertical axis through its center. Suddenly, a 70.0-kg parachutist makes a soft landing on the turntable at a point near the outer edge. (a) Find the angular speed of the turntable after the parachutist lands. (Assume that you can treat the parachutist as a particle.) (b) Compute the kinetic energy of the system before and after the parachutist lands. Why are these kinetic energies not equal?

157. assignment (standing sound waves)

Assignment text: Consider an experiment where a speaker sends waves down a tube with an open and closed end. If the experiment were to be redone at the same frequency with the speaker held firmly against the end of the tube, what would change: 1. the locations of the cap at resonance? 2. the internodal distance? 3. the wave speed in the tube?

158. assignment (angular resolution of the human eye)

Assignment text: An American standard analog television picture (non-HDTV), also known as NTSC, is composed of approximately 485 visible horizontal lines of varying light intensity. Assume your ability to resolve the lines is limited only by the Rayleigh criterion, the pupils of your eyes are 4.80 mm in diameter, and the average wavelength of the light coming from the screen is 560 nm. Calculate the ratio of the minimum viewing distance to the vertical dimension of the picture such that you will not be able to resolve the lines. viewing distance/vertical dimension =

159. assignment (Kirchhoff's voltage law)

Assignment text: In this circuit, R1 = 5 ohm ,R2 = 4 ohm,R3 = 4 ohm,R4 = 6 ohm,R5 = 4 ohm, C = 200microF 1. a) In the circuit below what is the current through and voltage across each resistor when switch 1 and 2 are closed?

160. assignment (laser)

Assignment text: He-Ne lasers are often used in physics demonstrations. They produce light of wavelength 633nm and a power of 0.900mW spread over a cylindrical beam 1.50mm in diameter (although these quantities can vary). a) What is the intensity of this laser beam? b) What is the maximum value of the electric field? c) What is the maximum value of the magnetic field? d) What is the average energy density in the laser beam?

161. assignment ( law of Malus)

Assignment text: Item 7 Two Polaroids are aligned so that the light passing through them is a maximum Part A At what angle should one of them be replaced so the intensity is subsequentially reduced by half?

162. assignment (thin wire diffraction)

Assignment text: An intern engineer is designing a set up based on a diffraction to measure the diameter of thin wires. He tested the setup by using a known wire diameter 0.03 mm. He used a coherent light source of wavelength 361 nm. He positioned the viewing screen 3.3 m from the wire. a) What is in m the position of the first diffraction minimum due to the light? b) What is in m the with delta y – central, of the central diffraction maximum? c) What is in m the position of the second order diffraction maximum? d) What is in m the with delta y of the second order maximum?

163. assignment (sound level)

Assignment text: A family ice show is held in an enclosed arena. The skaters perform to music with a sound level of 80 dB. This is too loud for a young child on your lap. The young child begins to yell at a level of 75 dB. What is the combined sound level?

164. assignment (lightning flash-thunder)

Assignment text: A rule for finding your distance from a lightning flash is to count seconds from the time you see the flash until you hear the thunder, and then divide the count by five. The result is supposed to give the distance in miles. Explain this rule and estimate the error in the distance (in percent) under standard conditions.

165. assignment (wavelength of an earthquake)

Assignment text: What is the wavelength of an earthquake that shakes you with a frequency of 11.0 Hz and gets to another city 86.0 km away in 12.0 s?

166. assignment (particle in a box)

Assignment text: Consider an atomic nucleus to be equivalent to a one-dimensional infinite potential well with L = 1.9 x 10-14 m, a typical nuclear diameter. What would be the ground-state energy (in GeV) of an electron if it were trapped in such a potential well? (Note: Nuclei do not contain electrons.)

167. assignment (pressure)

Assignment text: 6. A child wants to pump up a bicycle tire so that its pressure is 1.2*10^5 Pa above that of atmospheric pressure. If the child uses a pump with a circular piston with a surface area equal to 9.6*10^-4 m^2 what force must the child exert? A) 120N B) 89 N C) 76 N D) 54 N E) 240 N

168. assignment (diverging lens)

Assignment text: An object is placed 2.0cm in front of diverging lens, which has a power of -25 diopters. The image is located at?

169. assignment (rotational dynamics)

Assignment text: QUESTION 4*** If the can is released from rest, the kinetic energy of the can after it has dropped a distance h is (a) less than mgh. (b) equal to mgh. (c) larger than mgh. QUESTION 5** A uniform disk and a uniform sphere each have the same mass and radius and each roll without slipping with the same center of mass velocity on a horizontal surface. Which object has the most total kinetic energy? (a) The disk. (b) The sphere. (c) They both have the same total kinetic energy.

170. assignment (heat capacity)

Assignment text: How much heat is required to raise the temperature of 0.270kg of water from 19.8C to 31.4C? answer in J IF this amount of heat is added to an equal mass of mercury that is initially at 19.8C what is the final temp? answer in Celsius

171. assignment (fission reactor)

Assignment text: A fission reactor produces 1600MW of electric power. Assume it operates at 30% efficiency, with an average of 200 MeV produced in each fission event. At what rate is the 235U fuel consumed? rate needs to be in g/s

172. assignment (trigonometry)

Assignment text: Two balloons are tethered to one another. The left-hand balloon is tethered with a string along d1 to the ground. The right-hand balloon is tethered to the left-hand balloon with a string along d2. The heights of each balloon, h1and h2, the lengths of each string, d1 and d2, and the orientation angles, theta and phi, are as shown in the figure. Write an expression for the height of the left-hand balloon, h1, in terms of the given quantities. Expression : h1 = __________________________________________ Write an expression for the height of the right balloon, h2, in terms of h1 and the given quantities. We will define psi = phi - theta. Expression : h2 = __________________________________________

173. assignment (grain surface)

Assignment text: Grains of fine California beach sand are approximately spheres with an average radius of 80 µm and are made of silicon dioxide. A solid cube of silicon dioxide with a volume of 1.00 m3 has a mass of 2600 kg. What mass of small sand grains would have a total surface area (the total area of all individual spheres) equal to the surface area of a cube 1.00 m on an edge?

174. assignment (thermal efficiency)

Assignment text: A heat engine does 822.48 J of work per cycle while exhausting 163.31 J of waste heat. What is the engine's thermal efficiency in percent?

175. assignment (frictional force)

Assignment text: A 1,500-kg car is moving up a road with a slope (grade) of 11% while slowing down at a rate of 4.7 m/s^2. What is the direction and magnitude of the frictional force? (define positive in the forward direction, i.e., up the slope).

176. assignment (buoyant force)

Assignment text: One of the problems with debris in the ocean is that it is often difficult to see, because much of the object is under the surface of the water. An object with a density of p =711 kg/m3 and a mass m = 1759 kg is thrown into the ocean. Find the fraction f of the object that is sticking out of the water (use psea water = 1024 kg/m^3).

177. assignment (immersion heater)

Assignment text: An immersion heater has a power rating of 1300 watts. It is used to heat water for coffee. How long (in minutes) should it take to bring 0.8 L of water from room temperature (20°C) to 82°C?

178. assignment (relativistic kinetic energy)

Assignment text: An electron is accelerated inside a parallel plate capacitor. The electron leaves the negative plate with a negligible initial velocity and then after the acceleration it hits the positive plate with a final velocity . The distance between the plates is 15.7 cm, and the voltage difference is 121 kV. A) Determine the final velocity of the electron using classical mechanics. (The rest mass of the electron is 9.11×10-31 kg, the rest energy of the electron is 511 keV.) B) What is the final velocity ? of the electron if you use relativistic mechanics?

179. assignment (work and energy)

Assignment text: A bicyclist starting from rest applies a force of F = 109 N to ride his bicycle across flat ground for a distance of d = 180 m before encountering a hill making an angle of θ = 28 degrees with respect to the horizontal. The bicycle and rider have a mass of m = 111 kg combined. Part (a) How much work, W in joules, did the rider do before reaching the hill? Numeric : A numeric value is expected and not an expression. W = __________________________________________ Part (b) What is the bicycle's speed, v in m/s, just before the hill? Assume there is no kinetic friction between the bicycle and the ground. Numeric : A numeric value is expected and not an expression. v = __________________________________________ Part (c) If the cyclist starts coasting at the bottom of the hill, what distance, di in meters, does the bike travel up the incline? Numeric : A numeric value is expected and not an expression. di = __________________________________________

180. assignment (kinetic energy)

Assignment text: (a) How many joules of kinetic energy does a 80-kg person have when walking at 2 m/s? J How many joules of kinetic energy does a 80-kg person have when running at 6 m/s? J (b) In the Bohr model of the atom, the ground-state electron in hydrogen has an orbital speed of 2190 km/s. What is its kinetic energy? J (c) If you drop a 4.0 kg weight (about 9 lb) from shoulder height (1.6 m), how many joules of kinetic energy will it have when it reaches the ground?

181. assignment (electrical potential difference)

Assignment text: A proton moves from point A to point B in a region with a uniform electric field directed toward the left (towards point B). The only force action on the proton is the force due to the uniform electric field. The proton's change in the electric potential energy is -7.55x10-18 J. Calculate the electric potential difference VB-VA.

182. assignment (orbital period)

Assignment text: In a shuttle craft of mass m = 2000 kg, Captain Janeway orbits a planet of mass M = 5.98×1024 kg, in a circular orbit of radius r = 6.80×106 m. What are (a) the period of the orbit and (b) the speed of the shuttle craft? (a) the period (b) the speed Janeway briefly fires a forward-pointing thruster, reducing her speed by 6.0percent.(Assume that there was a negligible change in the mass of the craft). Just then, what are (c) the speed, (d) the kinetic energy, (e) the gravitational potential energy, and (f) the mechanical energy of the shuttle craft? (c) the speed (d) the kinetic energy (e) the gravitational potential energy (f) the mechanical energy of the shuttle craft (g) What is the semimajor axis of the elliptical orbit now taken by the craft? (h) What is the difference between the period of the original circular orbit and that of the new elliptical orbit?

183. assignment (carbon dating)

Assignment text: A sample of charcoal from an archaeological site contains 50.0g of carbon and decays at a rate of 0.887Bq . How old is it?

184. assignment (quantized angular momentum)

Assignment text: What is the maximum possible angular momentum L (as a multiple of ћ) of a hydrogen atom with energy -0.850eV ?

185. assignment (particle reactions)

Which of the following particle reactions can’t occur (Select all that apply.)

186. assignment (potential difference)

Assignment text: The figure below shows two point charges q1 = +5.6x10-8 C and q2 = -6.3x10-8 C. 1) Find the potential at A. 2) Find the potential at B. 3) Find the potential difference Va-Vb

187. assignment (projectile motion)

Assignment text: 13. Neglect air friction. A rifle bullet is shot at angle of 60 degrees from the ground at a speed of 2700 ft/s. Note: Be sure to use X and Y components. A. How high does the bullet go? B. How far does the bullet go down range? C. How long does it take to hit the ground.

188. assignment (rotational kinematics)

Assignment text: Problem 1 As shown in Fig. 1, a wheel of radius r =0.1 m and mass M= 10 kg is rolling (i.e. no slip between the wheel and the surface) back and forth on a circular surface of radius R=1 m. At the time when wheel reaches the bottom, the velocity of the mass center is v = 0.05 m/s pointing horizontally to the right. Calculate the following: a) Respective velocities of points A (bottom of the wheel), B (top of the wheel) and C (rearmost point of the wheel). b) Respective accelerations of points A, B and C on the wheel as indicated.

189. assignment (calorimetry)

Assignment text: 1. If mw = 250 g of liquid H2O is at 30°C, how much heat must be removed from it to reach a final temperature of 18°C? 2. How much thermal energy is required to melt an ice cube, mi = 35g, initially at 0 °C and raise it to a final temperature of 18°C? 3. Based on these two numbers alone, if the ice cube is dropped into the 250g of liquid H2O, would the final temperature be less than, equal to, or greater than 18°C? Explain your reasoning. (Hint: Consider whether there is less than enough or more than enough energy available, or exactly the right amount to melt and warm the ice to 18°C . What would happen in each situation?) 4. Consider now that the liquid water was originally contained in an aluminum cup, also initially at 30°C, What is the mass of the aluminum cup if the final temperature of the combined system of cup, original liquid water, and (now melted) ice cube is, in fact, 18°C?

190. assignment (photon)

Assignment text: What's the series limit for the Pfund experiment?

191. assignment (thin film interference)

Assignment text: A uniform thin film of alcohol (n=1.36) lies on a flat glass plate (n=1.56). When monochromatic light, whose wavelength can be changed, is incident normally, the reflected light is a minimum for lambda=516 nm and a maximum for lambda = 645 nm. What is the minimum thickness of the film?

192. assignment (kinetic energy)

Assignment text: Calculate speed of a roller-coaster cart when arriving at point (1), if when it was at point (2), was traveling with a speed of 10 m/s.

193. assignment (pendulum)

Assignment text: (a) Your pendulum clock which advances 1.0 s for every complete oscillation of the pendulum is running perfectly on Earth at a site where the magnitude of the acceleration due to gravity is 9.80 m/s2. You send the clock to a location on the Moon where the magnitude of the acceleration due to gravity is 1.65 m/s2. Does the clock run fast or slow on the Moon? A It runs fast. B It runs slow. C Neither, it runs the same as on Earth. (b) If the clock is started at 12:00 noon, what will it read after a time of 19.5 h has elapsed on Earth? Enter the time to the nearest minute. : PM

194. assignment (electric force)

Assignment text: 11. Electric force between two equal positive charges is 1 N. If the separation between the charges is 1m, what is the magnitude of each charge? 12. What is the electric field at a distance of 100 mm from a point charge of 1 C? 13. in a uniform electric field of 2 N/C, what amount of electric charge can be held with a 40 N force?

195. assignment (ice melting)

Assignment text: A 2.00 kg block of ice has a temperature of -10.0C. It is then placed outside during a 21.0 C day. How much energy will the block absorb before reaching thermal equilibrium with the outside air?

196. assignment (projectile motion)

Assignment text: Problem 36.3 This problem uses the fact that the velocity of a particle is always tangent to the path of the particle. A block is propelled by a conveyor belt and released at point 0 with unknown velocity vo. The block is a projectile from 0 to A. At A the block slides onto a ramp AB, and slides down until it comes to a stop. Determine the following: 1. The velocity of the conveyor belt, V0. 2. The angle, theta, of the ramp AB if the ramp is to be parallel to the block velocity VA when the block slides onto the ramp. 3. The distance slid by the block until it comes to a stop. The friction coefficient between the ramp and the block is 0.8.

197. assignment (rotational inertia and torque)

Assignment text: Swinging Holiday Fun A holiday ornament in the shape of a hollow sphere with a mass of 15 grams and a radius of 5.5 cm is hung from a tree limb by a small loop of wire attached to the surface of the sphere. If the ornament is displaced a small distance and released, it swings back and forth as a physical pendulum. You can ignore any possible friction at the pivot. A. What is the rotational inertia for the hollow spherical ornament about the pivot at the tree limb? The rotational inertia for a hollow sphere about its center of mass is 23 MR2. B. Suppose the ornament were displaced from equilibrium by an angle of 5.5 degrees and released from rest. Calculate the magnitude of the torque on the ornament, about the pivot at the tree limb, at the instant immediately after release. C. Calculate the angular frequency and the period of the motion of the swinging ornament. D. Calculate the maximum kinetic energy of the swinging ornament if it is displaced from equilibrium by an angle of 5.5 degrees and released from rest.

198. assignment (coke cooling)

Assignment text: How much wattage is needed to cool down 355 ml of coke 15 degree Celsius in 15 minutes? Show the equation needed.

199. assignment (magnetic field vector)

Assignment text: A+6.00 -microC point charge is moving at a constant 8.5*10^6 m/s in the +y direction, relative to a reference frame, what is the magnetic field vector B it produces at the following points. Part A x=0.5m, y=0, z=0 Part B x=0, y=0, z=0.5 m Part C x=0, y= - 0.5m, z= 0.5 m

200. assignment (rlc short answers)

Please explain why these are true/false or always true/false: [1] In a capacitor in an AC circuit, the electric field leads the current. [2] The impedance of a capacitor increases with frequency. [3] In an LR circuit with a switch, the current through the inductor when the switch has been closed for a long time is zero. [4] The voltage across a capacitor in a DC circuit approaches its final value exponentially. [5] To make a high pass filter, use an RC circuit with the output voltage measured across the capacitor. [6] In an RC circuit, the electric and magnetic fields reach their maximum values at the same time. [7] In an ideal transformer (no energy loss), the side with more turns gives a higher voltage and larger current than the side with fewer turns. [8] The inductance of a coil depends on the number and size of the coils and the material in the wire. [9] The capacitance of a capacitor is decreased by placing a material with a higher dielectric constant between the plates. [10] Like resistors, inductors in series and capacitors in series add, while inductors and capacitors in parallel combine as the reciprocals. [11] Once the initial phasors for an AC circuit are plotted, they each rotate at different rates as time progresses.

201. assignment (pressure of the gas )

Assignment text: Gas is confined in a tank at a pressure of 11.1 atm and a temperature of 26.5 C. If two-thirds of the gas is withdrawn and the temperature is raised to 79.0 C, what is the pressure of the gas remaining in the tank?

202. assignment (center of mass)

Assignment text: Which point is the center of mass?

203. assignment (harmonics)

Assignment text: A string fixed at both ends is 2.5 m long. It resonates in its second harmonic at a frequency of 30 Hz. What is the speed of transverse waves on the string? Answer in units of m/s

204. assignment (time dilation)

Assignment text: After being created in a high-energy particle accelerator, a pi meson at rest has an average lifetime of 2.60 10-8 s. Traveling at a speed very close to the speed of light, a pi meson travels a distance of 149 m before decaying. How fast is it moving?

205. assignment (volume of a human heart)

Assignment text: Estimate the volume of a human heart (in mL) using the following measurements/assumptions: Blood flow through the aorta is approximately 15.5 cm/s The diameter of the aorta is approximately 3.0 cm Assume the heart pumps its own volume with each beat Assume a pulse rate of 90 beats per minute

206. assignment (induction)

Assignment text: A circular metal ring is suspended above a solenoid. The magnetic field due to the solenoid is shown in the figure below . The current in the solenoid is increasing. (a) What is the direction of the current in the ring? (b) The flux through the ring is proportional to the current in the solenoid. When the current in the solenoid is 12.0 A, the magnetic flux through the ring is 0.40 Wb. When the current increases at a rate of 240 A/s, what is the induced emf in the ring? (c) Is there a net magnetic force on the ring? If so, in what direction?

207. assignment (mechanical energy)

Assignment text: A 0.25 kg object is suspended on a light spring of spring constant 39N/m . The spring is then compressed to a position 15cm above the stretched equilibrium position. How much more energy does the system have at the compressed position than at the stretched equilibrium position? (answer in Joules)

208. assignment (vertical motion)

Assignment text: A tennis ball is shot vertically upward in an evacuated chamber with an initial speed of 20.0m/s at time t=0 a) how high does the ball rise? b) how long does it take the tennis ball to reach its maximum height?

209. assignment (gas in a container)

Assignment text: a) If 0.8 mol of a gas in a container occupies a volume of 14.0 l at a pressure of 1.0 atm, what is the temperature of the gas (in K)? b) The container is fitted with a piston so that the volume can change. When the gas is heated at constant pressure, it expands to a volume of 22.0 l. What is the temperature of the gas (in K)? c) The volume is fixed at 22.0 l, and the gas is heated at constant volume until its temperature is 353.0 K. What is the pressure (in atm) of the gas now?

210. assignment (basic physics)

Assignment text: 13. If you leave the door of your refrigerator open while it is operating, it a.) will cause the room to get cooler. b.) will cause the room to get warmer. c.) will not affect the temperature of the room. d.) could make the room cooler, warmer, or have no affect depending on the control settings of the refrigerator. e.) either heats or cools the room depending on whether it is summer or winter. 14. Blocks I and II, each with a mass of 1.0kg, are hung from the ceiling of an elevator by ropes 1 and 2. What is the force exerted by rope 1 on block II when the elevator is accelerating downward at 1m/s2? (Take g=10m/sl.) a.) 10 N b.) 2 N c.) 9N d.) 11 N e.) 0 N 15. In a given reversible process, the temperature of an ideal gas is kept constant while the gas is compressed to a smaller volume. Select the true statement: a.) The gas must absorb heat from its surroundings during this process. b.) The gas must release heat to Its surroundings during this process c.) The pressure of the gas also stays constant during this process. d.) The process is adiabatic. e.) it is Impossible to predict on the basis of this dam 16. in the figure above, M1 greater than M2, and both are sitting on a frictionless table. We can apply a horizontal force F from either the right or the left to move the two blocks. The magnitude of the force between masses M1 and M2 is a.) 0.0 N b.) larger when F is applied from the left. c) larger when F is applied from the right. d.) the same in either case, but not zero. e.) impossible to determine with this data.

211. assignment (basic physics)

Assignment text: 3. When you make ice cubes (from water), the entropy of the water a.) Decreases. b.) Remains unchanged. c.) Increases. d.) Is unchanged as the water cools but decreases as the water freezes. e.) Decreases while the water is cooling but does not change as it turns to ice. 4. A block with a mass 14=4.85kg begins at rest at the top of a curved slide. There is no friction. The speed of the block after it has slid along the slide sufficiently far for its vertical drop to be 19.6 m is a.) 19.6 m/s b.) 384 m/s c.) 73m/s d.) 43.2 m/s 5. You are pedaling a bicycle at 9.8m/s. The radius of the wheels of the bicycle is 51.9 cm. The magnitude of the angular velocity of the wheels is a.) 19 rad/s b.) 2.4 rad/s c.) 4.5 rad/s d.) 3.0 rad/s e.) 6.3 rad/s 6. On a graph that shows velocity on the vertical axis and time on the horizontal axis, the area under the curve represents a.) Displacement b.) average speed c.) average velocity. d.) average acceleration. e.) no useful physical quantity 7. A flatbed truck is carrying a crate along a level road. The coefficient of static friction between the crate and the bed of the truck is 0.40. The truck accelerates forward and the crate stays in place on the truck bed. In what direction with respect to the driver is the frictional force that the bed exerts on the crate? a.) There is no frictional force because the crate does not move with respect to the bed. b.) To the left c.) To the right d.) Forward e.) Backward

212. assignment (focal point)

Assignment text: You want to create a spotlight that will shine a bright beam of light with all of the light rays parallel to each other. You have a large concave spherical mirror and a small lightbulb. Where should you place the lightbulb? a. at the point, because all rays bouncing off the mirror will be parallel. b. at the focal point of the mirror c. at the radius of curvature of the mirror d. none of the above, you cant make parallel rays with a concave mirror

213. assignment (electric field)

Assignment text: A point charge -2.06nC is at the point x = 0.60 m, y = 0.80 m , and a second point charge 5.57nC is at the point x = 0.60 m , y = 0. Calculate the direction of the net electric field at the origin due to these two point charges. COUNTER CLOCKWISE FROM THE +X DIRECTION.

214. assignment (thin film interference)

Assignment text: An oil drop (n = 1.20) floats on the surface of water (n = 1.33) and is viewed from overhead when illuminated by sunlight shining vertically downward and reflected vertically upward. (a) Are the outer (thinnest) regions of the drop bright or dark? The oil film displays several spectra of colors. (b) Move from the rim inward to the third blue band and, using a wavelength of 475 nm for blue light, determine the film thickness there. (c) If the oil thickness increases, why do the colors gradually fade and then disappear?

215. assignment (electric force)

Assignment text: What is the magnitude of the vertical electric field that will balance the weight of a plastic sphere of mass 2.1 grams that has been charged to -3.0 nC? (k = 1/4πξ0 = 9.0 × 109 N · m2/C2) A) 6.9 × 10^6 N/C B) 7.8 × 10^5 N/C C) 1.5 × 10^6 N/C D) 2.1 × 10^6 N/C

216. assignment (nuclear mass defect)

Assignment text: The following masses are known: n (neutron) 1.008665 u H (hydrogen atom) 1.007825 u Ra (radium 226) 226.025403 u What is the binding energy of Ra 226? (1 u=931.5MeV/c^2)

217. assignment (refraction)

Assignment text: A fisherman sees rays of light apparently diverging from a point P' on a fish (see figure below). The fish appears to be at y = 1.1 m below the surface. What is its actual depth? (Take θ = 41.2°.)

218. assignment (angular magnification)

The objective of a certain microscope provides an angular magnification of 47. The image is 22 cm from the objective. How far is the object from the objective?

219. assignment (electric force)

Assignment text: Three point charges are arranged at the points of a right triangle. Imagine them on an x/y axis with Q2= 6nC at the origin, Q1= 3nC and is .03m above Q2, and then Q3=25nC which is .04m to the right of Q2.

220. assignment (rotation)

Assignment text: What is the time for one complete revolution for a very high-energy proton in the 1.0-km-radius Fermilab accelerator?

221. assignment (Kirchhoff's loop rule)

Assignment text: In the circuit shown in (Figure1) R1=6.0 ohm, R2=5.0 ohm, R3=7 ohm, Epsilon 1=10 V, Epsilon 2=2.0 V

222. assignment (electric field-current)

Assignment text: In (Figure 1), the wire connecting the positive battery terminal to the top end of the resistor is 100 mm long, and the wire connecting the negative battery terminal to the bottom end of the resistor is also 100 mm long. The resistor is 10 mm long, Select the correct conclusions from the comparison of the resistances of the resistor and he wire segments connecting he battery and the resistor. -Correct statement- • The resistances of the wire segments connecting the battery and the resistor can be assumed negligible compared to the resistance of the resistor, therefore the potential differences across he wire segments are negligible compared to the potential difference across the resistor, and the electric field magnitudes inside the wire segments are negligible compared to the electric field magnitude in the resistor, so it can be claimed to a good approximation that Ea=0 and Eb=0 compared to the electric field magnitude in the resistor.

223. assignment (motion of a charged particle in a uniform electric field)

Assignment text: The Figure shows an electron passing between two charged metal plates that create a 110N/C vertical electric field perpendicular to the electron’s original horizontal velocity. The initial velocity of the electron is 3.30x 106 m/s along the x direction, and the horizontal distance it travels in the uniform field is 4.30cm. a) What is in m/s2 the vertical acceleration of the electron while between the parallel plates? b) For how long, in seconds, will the electron be between the plates? c) What is in m/s the vertical component of the velocity as the electron exits the metal plates? d) What is the vertical deflection (displacement) of the electrons due to the plates? e) At what angle θ (in degrees) do the electrons exit the plates? Use 9.1 x 10-31 kg for the mass of the electron. Neglect any edge effects.

224. assignment (relativistic kinetic energy)

Assignment text: Find the potential difference through which a proton must be accelerated to give it a final speed of 0.607c, starting from rest.

225. assignment (momentum conservation)

Assignment text: Two astronauts on opposite ends of a spaceship are comparing lunches. One has an apple, the other has an orange. They decide to trade. Astronaut 1 tosses the 0.130kg apple toward astronaut 2 with a speed of vi,1 = 1.05m/s . The 0.170kg orange is tossed from astronaut 2 to astronaut 1 with a speed of 1.19m/s . Unfortunately, the fruits collide, sending the orange off with a speed of 0.946m/s in the negative y direction. Calculate direction of the apple.

226. assignment (Kirchhoff's loop rule)

Assignment text: V1=3.0 V, V2=21.0 V, R1=58.0 ohm, R2=56.0 ohm. What is the current in this circuit?

227. assignment (magnetic field)

Assignment text: Consider (in 3 dimensions) a regular square lattice of wires spaced 1 cm apart, each carrying a current of 0.5 A, with the direction of the current alternating in adjacent wires. Let the wires all run in the z direction, with the ones at (0,0) cm, (0,2) cm, (2,0) cm, (2,2) cm and (1,1) cm carry current into the page, with (0,1) cm, (1,0) cm, etc. carrying current out. What does the magnetic field between adjacent wires look like? While a completely accurate answer would require some infinite series or extreme cleverness, just try to draw a rough map of where the field point over the square from the origin to (2,2) cm, with the understanding that each wire dominates its local neighborhood. Then calculate the field at (0.5, 0.5) cm.

228. assignment (particle oscillation)

Assignment text: The position of a particle in cm is given by x = (8) cos2πt, where t is in seconds. 1) (a) What is the frequency? 2) (b) What is the period? 4) (d) What is the first time after t = 0 that the particle is at its equilibrium position?

229. assignment (Doppler effect)

Assignment text: At rest a car horn sounds A (440Hz) the horn is sounded while the car is moving at a velocity v. A bicycle is moving in the same direction as the car, but with a velocity of v/3 and hears the horn with apparent frequency of 415Hz. the speed of sound in air is 345. a) is the bicycle in front of or behind the car? b) what is the speed of the car?

230. assignment (heat)

Assignment text: 1. A heat engine uses resistors to boil water as part of its operation. There are 3 resistors with resistances 25 ohms, 10 ohms, and 15 ohms connected in series. The resistors are connected to a 240 V power source. a. (2) What is the equivalent resistance of the three resistors? b. (2) How much electric power is dissipated in the resistors (all together)? d. (3) The engine extracts 1200 kJ of heat from the steam each cycle, and does 345 kJ of work. What is the engines efficiency?

231. assignment (activity)

Assignment text: 5. A sample of Polonium-206 starts out with an activity of 2000 Bq (decays/s). The half-life of Polonium-206 is 8.8 days. If you measure the activity 30 days later, what activity will you measure?

232. assignment (hydroelectric power)

Assignment text: 14.7 A hydroelectric power plant draws water from a lake whose surface is 55 m above the turbines. It draws the water through pipe with radius 1.2 m. (Patm = 100 kPa, ro-water = 1000 kg m^-3) (a) If, at point A, 55 m below the surface of the lake, the pipe is horizontal and the water is flowing through it at a rate of 9 m s^-1, at what pressure is the water? (Hint: compare this point to the surface of the lake using Bernoulli's Law. (b) In order for the turbines to work most efficiently the water should enter them at a speed of 20 ms^-1. In order to achieve this the pipe narrows to what radius just before it enters the turbines? (c) What is the pressure just before the water enters the tur-bines? (d) After passing through the turbines the water is now open to the atmosphere again. At what speed is it traveling (assuming that only a negligible fraction of the energy contained in the flow is removed by the turbines).

233. assignment (Compton scattering)

Assignment text: An x-ray of wavelength 30 pm is scattered 37o by an electron. What is the wavelength of the scattered photon?

234. assignment (magnetic force)

Assignment text: In a mass spectrometer, a single-charged particle (charge e) has a speed of 1.0 × 106 m/s and enters a uniform magnetic field of 0.20 T. The radius of the circular orbit is 0.020 m. What is the mass of the particle?

235. assignment (RLC circuit)

Assignment text: An RLC series circuit has a 4.00 kiloohms resistor, a 43 millihenry, and a 22 nano-farads capacitors. a) Find the circuit’s impedance in ohms at 480 Hz b) Find the circuit’s impedance in ohms at 14.40 Hz c) If the voltage source has Vrms=130V, what is in Amps the Irms at 14.40 kHz? d)What is in Hz the resonant frequency of the circuit? e) What is in ohms the impedance at resonance?

236. assignment (RLC circuit)

Assignment text: An RLC series circuit has a 2.10 kΩ resistor, a 82mH inductor, and a 45nF capacitor. a) Find the circuit’s impedance in Ω at 510Hz. b) Find the circuit’s impedance in Ω at 15.30kHz. c) If the voltage source has Vrms =130V, what is in Amps the Irms at 15.30kHz? d) What is in Hz the resonant frequency of the circuit? e) What is in Ω the impedance at resonance?

237. assignment (refractive index)

Assignment text: The speed of light in a dense glass is measured at 1.64×108 m/s . The refractive index of this glass is:

238. assignment (induced emf)

Assignment text: A long, straight wire runs along the y-axis. The wire carries a current in the positive y-direction that is changing as a function of time of time according to I= 2.0 A + (0.300 A/s)t. A loop of wire is located in the xy-plane near the y-axis, as shown in the figure. The loop has dimensions 7.00 m by 5.00 m and is 1.00 m away from the wire. What is the induced potential difference in the wire loop at t = 10.0 s?

239. assignment (ferromagnetic)

Assignment text: A magnet is attracted to a piece of unmagnetized ferromagnetic material (e.g., a refrigerator magnet on a refrigerator). In some detail explain the nature of the interaction between the magnet and the metal. On a microscopic level, where does the force of attraction come from?

240. assignment (electrical conductivity)

Assignment text: An aluminum wire 1.0 mm in diameter is to offer a resistance of no more than 20 ohm. Using the data in table, compute the maximum wire length.

241. assignment (quantum numbers)

Assignment text: An electron is in the hydrogen atom with n=3. A. Find the possible values of L and Lz for this electron, in units of ћ.

242. assignment (light wave)

Assignment text: A light wave travels, as a plane wave, from air (n=1.0) into glass (n=1.5). Which diagram shows the correct wave fronts?

243. assignment (parallel resistors)

Assignment text: If a 12-V battery is connected in parallel across resistors of 30 Ω, 60 Ω, and 120 Ω, the current pulled off of the battery is equal to:

244. assignment (rotational dynamics)

Assignment text: 6. You have a lab setup to investigate rigid body rotation. A uniform disk of mass 1kg and radius 10cm can rotate around its center. It is accelerated by a string that is wound around the outside of the disk and pulled on by a mass of 1/4 kg. (See sketch). You start the experiment from rest. a) Make a free body diagram for the pulling mass and a torque diagram for the disk. b) Write the relevant newton's equations for linear and rotary acceleration. Solve for the unknown accelerations and tension in the string. Recall the relation between angular and linear acceleration! C) After 0.5 sec by what angle has the disk spun and what is its angular speed at that moment.

245. assignment (center of mass)

Assignment text: Dr. L. (the rectangle) stands on one end of a boat and he is carrying Kepler (the oval). The system is initially at rest. The boat is mass 12M, Dr. L. is 3M and Kepler is mass M. The boat is a total length of 2L and its mass its evenly distributed. The boat can move without friction on the surface of the water. B.) (4pts) Kepler sticks to the left edge of the boat and comes to a stop. Where is the center of mass of the system? Your answer should be in terms of L only.

246. assignment (internal energy)

Assignment text: A model steam engine of 1.00-kg mass pulls eight cars of 1.00-kg mass each. The cars start at rest and reach a velocity of 5.00 m/s in a time of 5.00 s while moving a distance of 5.30 m. During that time the engine takes in 135 J of heat. What is the change in the internal energy of the engine? _____J

247. assignment (torque equilibrium)

Assignment text: A uniform rod of mass 10 kg and length of 3m is supported by a rope as shown. On the far end of the rod a block of mass 8 kg is suspended. The system is in equilibrium. What is the distance, d, from the left end of the rod to where rope is attached?

248. assignment (friction as a centripetal force)

Assignment text: A car traveling on a flat (unbanked) circular track accelerates uniformly from rest with a tangential acceleration of 1.70-m/s^2. The car makes it one fourth of the way around the circle before it skids off the track. What is the coefficuient of static friction between the car and the track?

249. assignment (inelastic collision)

Assignment text: The two cars are about to suffer an inelastic collision at the intersection. Find the speed of the combined masses immediately after collision. What fraction of the initial kinetic energy is lost in the collision?

250. assignment (light wavelength)

Assignment text: The energy levels for doubly charged lithium is given by: En=-13.606Z^2/n^2 eV where Z=3 for lithium. For each of the fallowing transitions determine the wavelength in nanometers and tell where in the electromagnetic spectrum that wavelength is located. a. n=7 to n=5 b. n=7 to n=4 c. n=6 to n=4 h=4.136*10^-15 eV/Hz c=2.997*10^8 m/s

Link to PDF s from 251 to 350

Link to PDF s from 251 to 350

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Link to PDF s from 351 to 502

Link to PDF s from 351 to 502

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