8.4 Elastic collisions in one dimension  (Page 4/8)

Two cars (A and B) of mass 1.5 kg collide. Car A is initially moving at 12 m/s, and car B is initially moving in the same direction with a speed of 6 m/s. The two cars are moving along a straight line before and after the collision. What will be the change in momentum of this system after the collision?

1. −27 kg • m/s
2. zero
3. +27 kg • m/s
4. It depends on whether the collision is elastic or inelastic.

Two cars (A and B) of mass 1.5 kg collide. Car A is initially moving at 24 m/s, and car B is initially moving in the opposite direction with a speed of 12 m/s. The two cars are moving along a straight line before and after the collision. (a) If the two cars have an elastic collision, calculate the change in momentum of the two-car system. (b) If the two cars have a completely inelastic collision, calculate the change in momentum of the two-car system.

Puck A (200 g) slides across a frictionless surface to collide with puck B (800 g), initially at rest. The velocity of each puck is measured during the experiment as follows:

What is the change in momentum of the center of mass of the system as a result of the collision?

1. +1.6 kg•m/s
2. +0.8 kg•m/s
3. 0
4. −1.6 kg•m/s

For the table above, calculate the center-of-mass velocity of the system both before and after the collision, then calculate the center-of-mass momentum of the system both before and after the collision. From this, determine the change in the momentum of the system as a result of the collision.

Two cars (A and B) of equal mass have an elastic collision. Prior to the collision, car A is moving at 15 m/s in the + x -direction, and car B is moving at 10 m/s in the – x -direction. Assuming that both cars continue moving along the x -axis after the collision, what will be the velocity of car A after the collision?

1. same as the original 15 m/s speed, opposite direction
2. equal to car B’s velocity prior to the collision
3. equal to the average of the two velocities, in its original direction
4. equal to the average of the two velocities, in the opposite direction

Two cars (A and B) of equal mass have an elastic collision. Prior to the collision, car A is moving at 20 m/s in the + x -direction, and car B is moving at 10 m/s in the – x -direction. Assuming that both cars continue moving along the x -axis after the collision, what will be the velocities of each car after the collision?

A rubber ball is dropped from rest at a fixed height. It bounces off a hard floor and rebounds upward, but it only reaches 90% of its original fixed height. What is the best way to explain the loss of kinetic energy of the ball during the collision?

1. Energy was required to deform the ball’s shape during the collision with the floor.
2. Energy was lost due to work done by the ball pushing on the floor during the collision.
3. Energy was lost due to friction between the ball and the floor.
4. Energy was lost due to the work done by gravity during the motion.