Unit 4: Linear Momentum
Physics 1 · Unit 4 · Paper 3

Linear Momentum unit test

A test on this unit alone, marked as a percentage and a letter grade — for the test your class is actually sitting, rather than for May. Answer everything, then submit once: seeing the answer to question 3 before attempting question 4 makes the final percentage meaningless.

Paper 1Paper 2Paper 3
Each paper is built from this unit’s 37 terms and is the same for everyone, so a teacher can assign “Unit 4, Paper 3” and every student sits the identical test. Multiple choice is marked objectively; the written sections you mark yourself against the model answer and rubric.
Suggested time 36 min 33 points0/17 attempted
1

Impulse from a graph

2

Why collisions can ignore friction

3

Explosion problems

4

Recoil

5

Elastic collision

6

Perfectly inelastic collision

7

Center of mass

8

Momentum in a system with external forces

9

Perfectly inelastic collision speed

10

Inelastic collision

11

Identifying whether momentum is conserved

12

Momentum vs kinetic energy

Short answer 1. Define or explain: Momentum

3 pts

Short answer 2. Define or explain: Ballistic pendulum

3 pts

Short answer 3. Define or explain: Center-of-mass velocity

3 pts

Short answer 4. Define or explain: Why impulse spreads force over time

3 pts

Free response

9 pts

On a horizontal frictionless track, cart A (mass 0.50 kg) moves to the right at 4.0 m/s and collides with cart B (mass 1.5 kg), which is initially at rest. After the collision, cart A moves to the left at 1.0 m/s.

Calculate the velocity of cart B after the collision, including direction.

Determine whether the collision is elastic, supporting your answer with a calculation.

The carts are in contact for 0.050 s. Calculate the magnitude and direction of the average force exerted on cart A by cart B.

Calculate the velocity of the center of mass of the two-cart system before and after the collision, and explain what your result demonstrates.

A student claims the data must be wrong because cart A “bounced backward off a lighter object.” Evaluate this claim.