AP Physics Physics: Momentum, Impulse & Collisions

Question 1

What is the momentum of a 5 kg object moving at 10 m/s?

Accepted Answer

50 kg·m/s

Answer

Momentum p = mv = 5 kg × 10 m/s = 50 kg·m/s.

Question 2

The impulse-momentum theorem states that the net impulse on an object equals:

Accepted Answer

The change in momentum

Answer

The impulse-momentum theorem states J = Δp, meaning impulse equals the change in momentum.

Question 3

A net force of 100 N acts on a 0.5 kg ball for 0.05 s. What is the magnitude of the impulse?

Accepted Answer

5 N·s

Answer

Impulse J = FΔt = 100 N × 0.05 s = 5 N·s.

Question 4

Which of the following is a vector quantity?

Accepted Answer

Momentum

Answer

Momentum p = mv is a vector because it has both magnitude and direction, following the direction of velocity.

Question 5

A 2 kg object increases its velocity from 3 m/s to 7 m/s. What impulse was applied?

Accepted Answer

8 N·s

Answer

Impulse J = mΔv = 2 kg × (7 − 3) m/s = 8 N·s.

AP Practice Test