PHYSICS I 1 I FI WAL EXAM FALL 2006

55. A rock is dropped from a cliff. Neglecting friction the kinetic energy increases as and as .

56. A box of mass 20 kg is given an initial speed of 10 m/s at the bottom of an inclined plane. See figure to the right. If the coefficient of friction between incline plane and box is 0.20, how far up the plane in the direction of the plane will the box travel?

(a) 3.9 m (b) 5.4 rn m ( d ) 9.2 m (e) I I .I m

57. A 2000 kg car is moving around a circular track at a speed of 45 m/s as shown to the right. What is the centripetal force needed to keep the car moving in a circle?

a 27x1 0 toward center of circle u (b) 27x1 0 N away from center of circle

(c) 42x1 o3 N toward center of circle (d) 42x1 o3 N away from center of circle (e) 65x10~ N toward center of circle

58. A 2.5 kg box starting from rest slides down a hill and compresses a large spring whose stiffness constant is I80 Nlm as shown in the figure to the right. How far is the spring compressed ?

(a) 1.0 m G 5 3 ( c ) 2.0 rn (d) 2.5 m (e) 3.0 m

59. A 2000 kg car traveling west at 30 rnls collides with a 3000 kg truck traveling south at 25 mls. In the completely inelastic collision they lock bumpers and travel as a single object. What is the speed of the car truck combination after the collision?

(a) 18 mls (c) 20 mls (d) 21 mls (e) 22 mls

60. A force of 5.0 N is applied to a 30 kg frictionless solid grinding wheel initially at rest as shown to the right. What will be the speed of the wheel after 12 s?

(e) 3.7 revls

illF1 -,%

G G v a (b) 1.8 revls (c) 2.4 revls (d) 3.1 revfs

61. A heavy child sits down carefully on the edge of a slowly rotating merry-go-round. Next he walks along a radius to the center of the merry-go-round and finally he walks out along a radius half the way to the outer edge. The merry-go-round responds by going - then - then

(a) faster, slower, faster ((bJ slower, faster, s l o w 3 (c) faster, faster, slower (d) slower, faster, faster (e) slower, slower, slower

62. A guitar string 50 cm long with a mass of 0.40 g is vibrating in it's 4th harmonic at a frequency of 1320 Hz. What is the tension on the guitar string?

(a) 25 N (b) 42 N (c) 66 N @=3(e) 99 N

63. What is the frequency of the second harmonic for sound for the organ pipe shown to the right?

a 172 Hz (b) 343 Hz (c) 51 4 Hz (d) 686 Hz e) The 2nd harmonic for this pipe does not exist. a

64. A 20.0 kg lead brick is lowered deep into the ocean by a long rope. How much force must be exerted by the rope to keep the lead brick from sinking to the bottom?

(a)17.8N (b)20.0N (c)143N@(e)196N

65. Water flows through a pipe as shown. If the water velocity is 2.5 m/s at point A, what is the magnitude of the difference in pressure between points A and B?

66. A chemist determines that if 2200 J of heat are added to a 1.0 kg piece of a metal it's temperature increases by 9.6 CO. What is the metal? (calculation required)

(a) aluminum (b) copper (c) iron (d) lead

67. Which would cause a more serious burn: 30 g of steam or 30 g of liquid water, both at 100 CO; and why is this so?

(a) Water because it is than steam. Steam because of capacity. Steam because of vaporization.

steam. Water because its specific heat is greater than that of

(e) Either one would cause a burn of the same severity since they are both at the same temperature.

68. 100 g of water at 50C0 in a 200 g aluminum calorimeter cup is mixed with 100 g of ice at -1 5C0. The final temperature of the resulting ice-water mixture is OCO. How much ice was melted? Warning: This problem is longer than most.

69. A 100 W light bulb generates 95 W of heat that is dissipated through a spherical glass bulb that has a radius of 4.0 cm and a thickness of 0.80 mm. Determine the temperature difference between the inner and outer surfaces of the glass.

(a) 2.3 dm (c) 7.9 CO (d) 10 CO (e) 13 CO

70. Which of the following is not an example of convection?

(a) Smoke rises above a fire. (b) An eagle soars on a updraft of wind.

@A person gets a suntan on a beach. (d) Water cooks spaghetti. (e) An electric heater warms a room.

71. One of the two basic discoveries that proceeded the acceptance of the "big bang" theory of the evolution of the universe was that of the 3K background microwave radiation in 1965. What was the other basic discovery?

a) The observation of light from distance galaxies that was red shifted to lower frequencies.

(b) The observation of light from distance galaxies that was blue shifted to higher frequencies.

(c) The discovery of the quark gluon plasma from collisions of relativistic protons.

(d) The discovery of the quark gluon plasma from collisions relativistic gold nuclei.

(e) The observation of fusion of protons in stars that produces both heat and helium nuclei.

72. What is one of the purposes of the RHlC particle accelerator?

(a) Accelerate and collide beams of protons and anti-protons

(b) Accelerate and collide beams of electrons and positrons. Accelerate a gold beam that collides with a fixed target. Accelerate two gold beams that collide with each other. Accelerate and collide beams of electrons and protons.

73. Scientists working at the RHlC particle accelerator believe they may have created a new form of matter consisting of _.

(a) a hot plasma consisting entirely of anti-matter. (b) a hot plasma consisting of neutrons and protons. (c) a hot plasma consisting of gold nuclei and electrons.

a hot plasma consisting of a gas of quarks and gluons. a hot plasma liquid consisting of quarks and gluons.

74. The pressure in an ideal gas is reduced by half slowly while in a sealed rigid container. In the process 360 J of heat left the gas. What was the change in internal energy during this process?

(a) I 80 J (b) -1 80 J (c) 360 J (e) 720 J

75. 0.50 moles of helium are compressed adiabatically to 20% of the original volume. In the process 3600 J of work are performed. What is the change in the temperature of the gas? Hint: You need expression for internal energy of ideal

gas from chapter 14 formula list.

(a) 87 CO (b) 240 C 0 @ T a (d) 750 C0 (e) 920 C0

76. Possible statements of the second law of thermodynamics are given below: A. Heat flows spontaneously from hot to cold objects

but not spontaneously from cold to hot. B. The total entropy of the universe increases in any

process. C. The total entropy of the universe decreases in any

process. D. No engine can completely convert heat into work. E. No refrigerator can extract more heat from the cold

reservoir than the work applied to the system. Which of the above statements are true?

(a) All but C. (b) All but E. (d)A., C. and D. (e)A., D. an

77. A Carnot refrigerator operating at room temperature (20C0) is used to produce ice at OCO. If 1 o4 J of work is done, how much ice will be produced? Assume the water in the refrigerator is initially at OCO. Hint: First calculate the COF.

m ( b ) 0.50 kg (c) 0.58 kg (d) 0.65 kg (e) 0.72 kg

78. A 3.0 kg rock is dropped from a bridge and strikes the ground 45 m below. What is the change in the entropy of the universe? Assume this all happens at 20C0.

(@=3(b) -4.5 JIK (c) 18 J/K (d) -18 JIK (e) 66 Jlk