Practise Momentum of moving objects. 11 exam-style questions on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
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A cricket ball has a mass of 0.16 kg and travels at 25 m/s. Calculate the momentum of the ball. Use the equation: momentum = mass × velocity
4.0 kg m/s
Write down the equation that links mass (m), momentum (p) and velocity (v).
p = m v
A shopping trolley of mass 18 kg moves at 1.2 m/s. Calculate its momentum. Use the equation: momentum = mass × velocity
21.6 kg m/s
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy4 marks
(a) A cricket ball has a mass of 0.16 kg and travels at 25 m/s. Calculate the momentum of the ball. Use the equation: momentum = mass × velocity[2]
(b) What is the unit of momentum? Tick (✓) one box.[1]
kg m/s
kg m/s2
N/m
J/s
(c) Momentum is a vector quantity. What does this mean?[1]
Show the answer and mark scheme
(a)Answer: 4.0 kg m/s
p = 0.16 × 25
4.0 (kg m/s)
(b)Answer: kg m/s
(c)Answer: It has magnitude and direction.
it has both magnitude (size) and direction
Question 2Medium5 marks
(a) Write down the equation that links mass (m), momentum (p) and velocity (v).[1]
(b) A car of mass 1200 kg travels at 15 m/s. Calculate the momentum of the car.[2]
(c) A lorry of mass 9000 kg has the same momentum as the car. Calculate the velocity of the lorry.[2]
Show the answer and mark scheme
(a)Answer: p = m v
p = m v / momentum = mass × velocity
(b)Answer: 18 000 kg m/s
p = 1200 × 15
18 000 (kg m/s)
(c)Answer: 2.0 m/s
18 000 = 9000 × v
v = 2.0 (m/s)
Question 3Hard7 marks
A tennis ball of mass 0.058 kg and a bowling ball of mass 6.0 kg each have a momentum of 3.0 kg m/s.
(a) Calculate the velocity of the tennis ball.[2]
(b) Calculate the velocity of the bowling ball.[1]
(c) Calculate the kinetic energy of the tennis ball.[1]
(d) Calculate the kinetic energy of the bowling ball.[1]
(e) A student says: ‘Objects with the same momentum must have the same kinetic energy.’ Use your answers to explain why the student is wrong.[2]
Show the answer and mark scheme
(a)Answer: 52 m/s (51.7 m/s) m/s
v = 3.0 ÷ 0.058
52 (m/s)
(b)Answer: 0.50 m/s
3.0 ÷ 6.0 = 0.50 (m/s)
(c)Answer: 78 J (77.6 J) J
0.5 × 0.058 × 51.72 = 78 (J)
(d)Answer: 0.75 J
0.5 × 6.0 × 0.502 = 0.75 (J)
(e)Answer: The tennis ball has about 100 times more kinetic energy: for equal momentum, the lighter, faster object has more kinetic energy because KE depends on v².
the tennis ball has about 100 times as much kinetic energy as the bowling ball, even though their momenta are equal
kinetic energy depends on (speed)2, so for the same momentum the object with the smaller mass (and greater speed) has more kinetic energy