AQA GCSE PHYSICS · PAPER 1 · FOUNDATION & HIGHER
Exam Practice: Kinetic, elastic and gravitational potential energy
Kinetic, elastic and gravitational potential energy · Energy · Lesson 2 of 7 · 16 marks · 17 minutes
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Instructions
• Answer all the questions.
• Write your answers in the spaces provided.
• The marks for each question are shown in brackets - use this as a guide to how much to write.
• The answers are on separate pages at the back. Attempt every question before you look at them.
• Answer all questions. Use the mark allocation as a guide to how much to write.
Question 1 CALCULATE (2 marks)
A ball of mass 0.40 kg moves at 12 m/s. Calculate the kinetic energy of the ball. Use the equation: kinetic energy = 0.5 × mass × (speed)²
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(Total for Question 1 = 2 marks)
Question 2 CALCULATE (3 marks)
A person of mass 55 kg climbs a ladder to a height of 4.0 m. Calculate the increase in gravitational potential energy. Gravitational field strength = 9.8 N/kg. Give your answer to 2 significant figures.
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(Total for Question 2 = 3 marks)
Question 3 CALCULATE (3 marks)
A spring has a spring constant of 25 N/m. It is stretched by 6.0 cm. Calculate the elastic potential energy stored in the spring. Assume the limit of proportionality has not been exceeded.
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(Total for Question 3 = 3 marks)
Question 4 CALCULATE (4 marks)
The diagram shows a roller coaster car of mass 400 kg. It is released from rest at A. Gravitational field strength = 9.8 N/kg. (a) Calculate the gravitational potential energy stored when the car is at A. (b) Assume no energy is dissipated. Calculate the speed of the car at B.
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(Total for Question 4 = 4 marks)
Question 5 CALCULATE (4 marks)
A ball of mass 0.050 kg is thrown vertically upwards at 20 m/s. Assume there is no air resistance. Calculate the maximum height reached by the ball. Gravitational field strength = 9.8 N/kg.
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(Total for Question 5 = 4 marks)
TOTAL FOR PAPER = 16 MARKS
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Answers and mark scheme
Check your answer only once you have written one.
Question 1 (2 marks)
E_k = 0.5 × 0.40 × 12² = 28.8 J
• Correct substitution 1 mark
• 28.8 J 1 mark
Question 2 (3 marks)
E_p = 55 × 9.8 × 4.0 = 2156 J, which is 2200 J (2 s.f.)
• Correct substitution 1 mark
• 2156 J 1 mark
• 2200 J 1 mark
Question 3 (3 marks)
e = 0.060 m; E_e = 0.5 × 25 × 0.060² = 0.045 J
• Converts 6.0 cm to 0.060 m 1 mark
• Correct substitution 1 mark
• 0.045 J 1 mark
Question 4 (4 marks)
(a) E_p = 400 × 9.8 × 25 = 98 000 J. (b) At B, E_p = 400 × 9.8 × 5 = 19 600 J. Kinetic energy = 98 000 − 19 600 = 78 400 J. v = √(2 × 78 400 ÷ 400) = 19.8 m/s
• 98 000 J 1 mark
• Kinetic energy gained = 78 400 J 1 mark
• v² = 2E_k ÷ m 1 mark
• 19.8 m/s (accept 20 m/s) 1 mark
Question 5 (4 marks)
E_k = 0.5 × 0.050 × 20² = 10 J. This becomes gravitational potential energy: h = 10 ÷ (0.050 × 9.8) = 20.4 m
• Kinetic energy = 10 J 1 mark
• Kinetic energy equals gravitational potential energy at the top 1 mark
• h = E_p ÷ (mg) 1 mark
• 20 m (accept 20.4 m) 1 mark