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Question :
61. A neutron in a nuclear reactor makes an elastic : 2102128

61. A neutron in a nuclear reactor makes an elastic head-on collision with a carbon atom initially at rest. (The mass of the carbon atom is 12 times that of the neutron.) What fraction of the neutron's kinetic energy is transferred to the carbon atom?

A. 14.4%

B. 28.4%

C. 41.4%

D. 56.6%

62. Popeye, of mass 70 kg, has just downed a can of spinach. He accelerates quickly and stops Bluto, of mass 700 kg (Bluto is very dense), who is charging in at 10 m/s. What was Popeye's speed?

A. 10 m/s

B. 31 m/s

C. 50 m/s

D. 100 m/s

63. Mitch throws a 100-g lump of clay at a 500-g target, which is at rest on a horizontal surface. After impact, the target, including the attached clay, slides 2.1 m before stopping. If the coefficient of friction is *m* = 0.50, find the speed of the clay before impact.

A. 4.5 m/s

B. 12 m/s

C. 27 m/s

D. 36 m/s

64. Two identical 7-kg bowling balls roll toward each other. The one on the left is moving at +4 m/s while the one on the right is moving at -4 m/s. What is the velocity of each ball after they collide elastically?

A. Neither is moving.

B. -4 m/s, +4 m/s

C. +4 m/s, -4 m/s

D. -14 m/s, 14 m/s

65. A 5-kg object is moving to the right at 4 m/s and collides with another object moving to the left at 5 m/s. The objects collide and stick together. After the collision, the combined object:

A. is moving to the right.

B. is moving to the left.

C. is at rest.

D. has less kinetic energy than the system had before the collision.