CoStudyexam prep that shows its work
Open the study app

All certifications →Educational banks →

Home › Certifications › High school subjects › High School Physics › Momentum and Collisions

Momentum and Collisions — High School Physics practice questions

14 multiple-choice questions and 12 flashcards on Momentum and Collisions, about 9% of the High School Physics bank. Every one carries a written rationale.

Written and maintained by the CoStudy team · last updated 2026-10-12 · how we write and review questions

What this chapter covers

Momentum and Collisions is one of 11 chapters in CoStudy's High School Physics bank, and it holds 14 of the bank's 150 multiple-choice questions — roughly 9% of the total. That proportion is not arbitrary: chapters follow the certifying body's published exam outline, and the number of questions in each is set by that domain's published weight, so the share of your practice time this chapter takes matches the share of the real exam it accounts for.

Studying by chapter is worth doing once you have a diagnostic score. A single overall percentage tells you whether you are close; it does not tell you which domain is dragging. Working a weak chapter in isolation, and re-testing it in isolation, is the fastest way to move a score that has stalled — and it is why the mock exams in CoStudy report by domain rather than as one number.

Free Momentum and Collisions practice questions

7 questions drawn from this chapter, with the full rationale shown — the controlling principle behind the right answer, and why each wrong option tempts and fails.

Momentum is a vector, which means it has:

  1. magnitude only
  2. direction only
  3. no units
  4. magnitude and direction

Answer: D — magnitude and direction

D) Correct — Direction matters in collisions. A) Describes a scalar. B) It also has magnitude. C) It has units of kg·m/s.

What is the momentum of a 3 kg ball moving at 4 m/s?

  1. 24 kg·m/s
  2. 0.75 kg·m/s
  3. 12 kg·m/s
  4. 7 kg·m/s

Answer: C — 12 kg·m/s

C) Correct — p = mv. A) Uses ½mv² = 24 J, which is kinetic energy. B) Divides. D) Adds.

A 2 kg cart at 3 m/s hits a 1 kg cart at rest, and they stick together. What is their final speed?

  1. 3 m/s
  2. 6 m/s
  3. 1.5 m/s
  4. 2 m/s

Answer: D — 2 m/s

D) Correct — (2)(3) = (3)v, so v = 2. A) Ignores the added mass. B) Gives the momentum instead of the speed. C) Divides by 2 kg + 2 kg.

In an inelastic collision:

  1. kinetic energy is conserved but momentum is not
  2. momentum is conserved but kinetic energy is not
  3. neither is conserved
  4. both are conserved

Answer: B — momentum is conserved but kinetic energy is not

B) Correct — Some energy becomes heat or sound. A) Reverses the two. C) Momentum is conserved. D) Describes an elastic collision.

Airbags reduce injuries mainly because they:

  1. increase the stopping time, reducing force
  2. reduce the change in momentum
  3. increase the stopping force
  4. make the passenger lighter

Answer: A — increase the stopping time, reducing force

A) Correct — The same impulse spread over more time means less force. B) The car still stops. C) They decrease it. D) Mass doesn't change.

A truck and a bicycle have the same momentum. Which moves faster?

  1. The truck
  2. They move at the same speed
  3. It can't be determined
  4. The bicycle

Answer: D — The bicycle

D) Correct — Smaller mass needs greater speed for equal momentum. A) Its greater mass means lower speed. B) Different masses. C) p = mv decides it.

A 0.5 kg ball hits a wall at 4 m/s and bounces back at 4 m/s. What is the size of its change in momentum?

  1. 0 kg·m/s
  2. 4 kg·m/s
  3. 2 kg·m/s
  4. 8 kg·m/s

Answer: B — 4 kg·m/s

B) Correct — Δp = 0.5(4 − (−4)) = 0.5 × 8. A) Ignores the change in direction. C) Counts only one direction. D) Leaves out the mass.

Momentum and Collisions flashcards

3 cards from the 12 in this chapter.

A 1000 kg car at 20 m/s collides and sticks to a 1000 kg stationary car. Find their final velocity.

Conservation: (1000)(20) = (2000)v → v = 10 m/s.

What is an inelastic collision?

A collision where momentum is conserved but kinetic energy is not (some converted to heat, sound, deformation).

What is linear momentum?

p = mv. A vector quantity equal to mass times velocity. Units: kg·m/s.

Practise the full chapter

These are a sample. The full Momentum and Collisions chapter runs 26 items with per-chapter progress tracking, on the web and in the iOS app.

Open High School Physics in CoStudy →

Other High School Physics chapters

All High School Physics practice questions →