1. In an inelastic collision, what quantities are conserved?
a) momentum only
b) kinetic energy only
c) neither momentum nor kinetic energy
d) momentum and kinetic energy
e) It depends on the masses of the colliding objects.
2. 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) The original ball bounces back at -6 m/s and one ball moves to the right at +6 m/s.
b) The original ball bounces back at -6 m/s while the other three balls remain stationary.
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) All four balls move to the right at 1.5 m/s
3. A 3.0 kg ball of clay traveling at 10 m/s collides with a 30 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) 2.7 m/s
b) 33 m/s
c) 90 m/s
d) 2.8 m/s
e) 1.0 m/s
4. 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) a perfectly inelastic collision
b) an inelastic (but not perfectly inelastic) collision
c) More information is needed.
d) an elastic collision
e) This situation is impossible.
5. A 3000 kg truck moving at 14 m/s collides with a stationary 1300 kg passenger car, and the two stick together. Assuming that they are free to move afterward, what is the momentum of the truck+car object after the collision?
a) 13000 kg m/s
b) 9.8 kg m/s
c) 18000 kg m/s
d) 60000 kg m/s
e) 42000 kg m/s
1. d) momentum and kinetic energy
2. c) The original ball bounces back at -3 m/s and one ball moves to the right at +3 m/s.
3. d) 2.8 m/s
4. a) a perfectly inelastic collision
5. c) 18000 kg m/s