One sphere of mass 1 kg is moving at 5 m/s to the right until it collides with a stationary, 2 kg sphere. After the collision, both spheres travel to the right: the 1 kg sphere at 1 m/s, and the 2 kg sphere at 2 m/s. What kind of collision took place?
a) an elastic collision
b) an inelastic (but not perfectly inelastic) collision
c) This situation is impossible.
d) a perfectly inelastic collision
e) More information is needed.
2. Which of the following equipment is the best choice for investigating elastic or nearly elastic collisions?
a) crash test cars with front ends that crumple upon impact to absorb all the initial kinetic energy
b) marble launcher that causes two marbles to collide with each other
c) a ball of soft clay that flattens when it hits the ground
d) two sliding carts on a frictionless track that stick together after impact
e) dropping a bowling ball from a balcony so that it makes a dent in the dirt below
3. A 4.0 kg ball of clay traveling at 10 m/s collides with a 50 kg ball of clay traveling in the same direction at 2.0 m/s. What is their combined speed if the two balls stick together when they touch?
a) 140 m/s
b) 4.5 m/s
c) 2.6 m/s
d) 54 m/s
e) 1.0 m/s
4. A steel ball traveling at 6 m/s hits a stationary line of three steel balls. Which statement is true if the collision is perfectly elastic?
a) All four balls move to the right at 1.5 m/s
b) The original ball bounces back at -6 m/s and one ball moves to the right at +6 m/s.
c) The original ball bounces back at -3 m/s and one ball moves to the right at +3 m/s.
d) The original ball stops and a single ball moves to the right at 6 m/s.
e) The original ball stops and two balls move to the right at 3 m/s.
5. A sphere of mass 7 kg is moving at 4 m/s to the right until it smacks into a second stationary sphere of mass 4 kg. After the collision, both spheres travel to the right: the first sphere at 1.09 m/s, and the second sphere at 5.09 m/s. What kind of collision took place?
a) This situation is impossible.
b) More information is needed.
c) This is a perfectly inelastic collision.
d) This is an inelastic (but not perfectly inelastic) collision.
e) This is an elastic or nearly elastic collision.
1. b) an inelastic (but not perfectly inelastic) collision
2. b) marble launcher that causes two marbles to collide with each other
3. d) 54 m/s
4. c) The original ball bounces back at -3 m/s and one ball moves to the right at +3 m/s.
5. d) This is an inelastic (but not perfectly inelastic) collision.