Pearson Edexcel International GCSE in Physics · 4PH1 · Free · no account needed
Conservation of Momentum — exam questions
12 original Incandio exam-style questions on Conservation of Momentum, 29 marks, about 29 minutes of writing. Each one carries the command word, the tariff and the specification statement it assesses, exactly as a paper presents them. This is an original Incandio practice question, written to reflect the structure and demands of the qualification. It is not an official Pearson Edexcel past-paper question.
This is the practice set for Conservation of Momentum — the lesson that teaches it. Read the lesson first if the idea is new; come here when you want to find out whether you can turn it into marks. Completely free, no account needed to read.
What these questions ask of you
6 command words run through this set, and on Pearson Edexcel International GCSE Physics each one means something precise. Answering the wrong command is the commonest way a candidate who understands the lesson still loses the mark.
- Which (1 mark)
- one option chosen from the set given
- State (1 mark)
- one precise fact or definition
- Calculate (1–5 marks)
- select the equation, substitute, evaluate — and state the unit Misread as: giving a bare number with no equation and no unit
- Explain (2–4 marks)
- the physics that causes it, set out as a line of reasoning Misread as: describing the change without giving the physical reason for it
- Suggest (1–3 marks)
- a plausible answer applying taught physics to an unfamiliar arrangement
- Determine (1–4 marks)
- a value obtained by combining a reading or gradient with a relationship
Assessed on Paper 1 (4PH1/1P) and Paper 2 (4PH1/2P), against AO1, AO2, AO3.
Where these sit in the specification
Pearson Edexcel International GCSE Physics (4PH1) — statements 1.27 · 1.29 · 1.28. Incandio is aligned to this specification; it is not published by, endorsed by or affiliated with Pearson, and it reproduces none of Pearson's wording.
The 12 questions
Answer them on paper, then open the lesson's exam practice to have them marked. The mark scheme, the accepted and rejected answers and the annotated model answer are in Incandio and are not printed here — an answer beside its question is not practice.
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Table 1 — three collisions between trolleys on a frictionless track Before After collision 1 2.0 kg at 3.0 m/s hits 4.0 kg at rest the two move off together collision 2 3.0 kg at 4.0 m/s hits 3.0 kg at rest the first stops, the second moves off collision 3 a 5.0 kg trolley at rest explodes into two 1.0 kg at 4.0 m/s one way, 4.0 kg the other (a)
(2)Calculate
Calculate the total momentum before collision 1 in Table 1.
Table 1 — three collisions between trolleys on a frictionless track Before After collision 1 2.0 kg at 3.0 m/s hits 4.0 kg at rest the two move off together collision 2 3.0 kg at 4.0 m/s hits 3.0 kg at rest the first stops, the second moves off collision 3 a 5.0 kg trolley at rest explodes into two 1.0 kg at 4.0 m/s one way, 4.0 kg the other total momentum before collision 1 = ............................ kg m/s
(b)
(3)Determine
Determine the velocity of the trolleys after collision 1, using Table 1.
Table 1 — three collisions between trolleys on a frictionless track Before After collision 1 2.0 kg at 3.0 m/s hits 4.0 kg at rest the two move off together collision 2 3.0 kg at 4.0 m/s hits 3.0 kg at rest the first stops, the second moves off collision 3 a 5.0 kg trolley at rest explodes into two 1.0 kg at 4.0 m/s one way, 4.0 kg the other ............................ m/s
(c)
(2)Determine
Determine the velocity of the second trolley after collision 2 in Table 1.
Table 1 — three collisions between trolleys on a frictionless track Before After collision 1 2.0 kg at 3.0 m/s hits 4.0 kg at rest the two move off together collision 2 3.0 kg at 4.0 m/s hits 3.0 kg at rest the first stops, the second moves off collision 3 a 5.0 kg trolley at rest explodes into two 1.0 kg at 4.0 m/s one way, 4.0 kg the other ............................ m/s
(d)
(2)Determine
Determine the velocity of the 4.0 kg piece after the explosion in collision 3, and explain the sign of your answer.
Table 1 — three collisions between trolleys on a frictionless track Before After collision 1 2.0 kg at 3.0 m/s hits 4.0 kg at rest the two move off together collision 2 3.0 kg at 4.0 m/s hits 3.0 kg at rest the first stops, the second moves off collision 3 a 5.0 kg trolley at rest explodes into two 1.0 kg at 4.0 m/s one way, 4.0 kg the other velocity of the 4 = ............................ m/s
(Total for Question 1 = 9 marks)
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(1)Which
Which quantity is conserved in a collision between two objects?
Quantity A velocity B total momentum C kinetic energy D force (Total for Question 2 = 1 mark)
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(1)State
State Newton's third law.
(Total for Question 3 = 1 mark)
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(3)Calculate
A force of 250 N acts on a ball for 0.040 s. Calculate the change in the ball's momentum.
change = ............................ kg m/s
(Total for Question 4 = 3 marks)
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(3)Calculate
A 1.5 kg trolley moving at 4.0 m/s collides with a stationary 0.50 kg trolley and they move off together. Calculate their common velocity.
common velocity = ............................ m/s
(Total for Question 5 = 3 marks)
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(3)Explain
Explain why the momentum lost by one object in a collision is exactly the momentum gained by the other.
(Total for Question 6 = 3 marks)
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(2)Explain
Explain why the equal and opposite forces of Newton's third law do not cancel each other out.
(Total for Question 7 = 2 marks)
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(3)Suggest
A rifle recoils backwards when it is fired. Suggest why, using momentum.
The rifle — A rifle of mass 4.0 kg is held loosely and is at rest before firing. The bullet has a mass of 0.010 kg and leaves the barrel at 400 m/s. No external horizontal force acts on the rifle and bullet together.
(Total for Question 8 = 3 marks)
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(4)Calculate
A 1200 kg car moving at 15 m/s runs into a stationary 800 kg car and the two move off together. Calculate their common velocity immediately afterwards.
velocity = ............................ m/s
(Total for Question 9 = 4 marks)
Have them marked, then defend the answer
Practice tells you the mark; teaching it back tells you whether you understand it. On Incandio a topic counts as mastered only once you have taught it and defended it.
- Mark these questions — 12 questions, marked on Incandio against the authored scheme, with the mistake you actually made named.
- Teach it — explain Conservation of Momentum to Ember, an AI pupil who does not have it yet and asks the awkward question.
- Defend it — argue it against Christiaan Huygens over three rounds, marked against descriptors you can read first.
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Back to the lesson
- Conservation of Momentum — The bookkeeping rule that survives every collision — and why a force is really a rate of change of momentum.
- All of Incandio Physics · Incandio Exam Practice