66. A 5-kg object moving to the right at 4 : 2102129
66. A 5-kg object is moving to the right at 4 m/s and collides with a 4-kg object moving to the left at 5 m/s. The objects collide and stick together. After the collision, the combined object:
A. has the same kinetic energy that the system had before the collision.
B. has more kinetic energy than the system had before the collision.
C. has no kinetic energy.
D. has less momentum than the system had before the collision.
67. If a two-body collision is not head-on, then we may always assume that:
A. momentum is conserved.
B. kinetic energy is conserved.
C. neither momentum nor kinetic energy are conserved.
D. both momentum and kinetic energy are conserved.
68. In a system with two moving objects, when a collision occurs between the objects:
A. the total kinetic energy is always conserved.
B. the total momentum is always conserved.
C. the total kinetic energy and total momentum are always conserved.
D. neither the kinetic energy nor the momentum is conserved.
69. A billiard ball (Ball #1) moving at 5.00 m/s strikes a stationary ball (Ball #2) of the same mass. After the collision, Ball #1 moves at a speed of 4.35 m/s. Find the speed of Ball #2 after the collision.
A. 1.25 m/s
B. 1.44 m/s
C. 2.16 m/s
D. 2.47 m/s
70. A baseball infielder, mass 75.0 kg, jumps up with velocity 3.00 m/s and catches a 0.150-kg baseball moving horizontally at 50.0 m/s. Of the following, which is closest to the final momentum of the system, infielder and baseball?
A. 225 kg?m/s
B. 228 kg?m/s
C. 230 kg?m/s
D. 233 kg?m/s