Momentum Conservation (Explosion) — Practice Quiz

Question 1

A 10 kg shell at rest explodes into a 4 kg piece moving at 30 m/s and another piece. Velocity of the other piece:

Accepted Answer

−20 m/s

Answer

+20 m/s

Answer

+30 m/s

Answer

−30 m/s

Question 2

A 5 g bullet fired at 600 m/s from a 2 kg gun. Recoil speed of gun:

Accepted Answer

1.5 m/s

Answer

3 m/s

Answer

0.15 m/s

Answer

15 m/s

Question 3

Momentum is conserved in:

Accepted Answer

All collisions (isolated systems)

Answer

Only elastic collisions

Answer

Only inelastic collisions

Answer

Only 1D

Question 4

Two equal masses moving with equal but opposite velocities undergo perfectly inelastic collision. Their COM:

Accepted Answer

Has v = 0 after

Answer

Continues at original v

Answer

Has v doubled

Answer

Has v halved

Question 5

Why does an astronaut floating in space throw a tool in one direction to move in the opposite?

Accepted Answer

Conservation of momentum (astronaut + tool system)

Answer

Newton's first law

Answer

Air resistance

Answer

Gravity