Newton’s Laws of Motion and Momentum | OCR A-Level Physics A (H556)
Newton’s Laws of Motion and Momentum
- 43 questions
- 4 subtopics
- Module 3: Forces and motion
- Paper 1 and Paper 3
Newton's three laws stated properly, momentum as the quantity his second law really concerns, impulse, and the conservation of momentum in collisions..
It covers newton's three laws and linear momentum, force as rate of change of momentum, impulse and force-time graphs and conservation of momentum and collisions.
Sample questions from Newton’s Laws of Motion and Momentum
Answer each one closed book first, then open the answer.
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Newton's three laws and linear momentum
What are the SI units of momentum?
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kg m s⁻¹ (or equivalently N s). -
Newton's three laws and linear momentum
What condition must be met for an object to remain at rest or continue moving at constant velocity?
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There must be no resultant force acting on the object. -
Force as rate of change of momentum
How is resultant force related to the rate of change of momentum?
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The resultant force acting on an object equals the rate of change of its momentum. -
Force as rate of change of momentum
Explain how airbags reduce the force experienced by a car occupant during a collision.
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Airbags increase the time over which the occupant's momentum changes; since impulse equals change in momentum, a longer time means a smaller average force. -
Impulse and force-time graphs
Define impulse.
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Impulse is the product of force and the time for which it acts. -
Impulse and force-time graphs
Calculate the impulse when force = 533 N, time interval = 0.227 s.
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Impulse = 533 × 0.227 = 121 N s. -
Conservation of momentum and collisions
Define a perfectly elastic collision.
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A collision in which both momentum and kinetic energy are conserved. -
Conservation of momentum and collisions
How does the scientific community use analysis of collision forces to improve vehicle safety?
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By investigating the forces involved in collisions, researchers develop safety features (such as crumple zones and airbags) designed to reduce the likelihood of personal injury.
The 4 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Newton's three laws and linear momentum | Recall questions on Newton's first and third laws, linear momentum, its equation, units and calculation, and momentum as a vector quantity. | 10 |
| Force as rate of change of momentum | Recall questions on Newton's second law in terms of momentum, resultant force as rate of change of momentum, when F = ma applies, and how airbags and longer collision times reduce force. | 9 |
| Impulse and force-time graphs | Recall questions on impulse, its equation, units and calculation, its relationship to change in momentum, and finding impulse from the area under linear and non-linear force-time graphs. | 8 |
| Conservation of momentum and collisions | Recall questions on the conditions for and principle of conservation of momentum, elastic and inelastic collisions, collision forces and vehicle safety, and momentum in one- and two-dimensional collisions with calculations. | 16 |
How the guide is worked
Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.
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Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
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Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
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Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
Read the full method, the return schedule and the research behind it.
Nearby topics
OCR A-Level Physics A Active Recall Guide
Every topic, not just this one. 1,862 questions with their answers.