A-Level Physics H2 Quiz - Energy Power
Name: ____________________
Class: ____________________
Date: ____________________
Score: ________ / 55
Duration: 60 Minutes
Total Marks: 55 Marks
Instructions:
- Answer all questions.
- Show all working clearly for calculation questions.
- Use g=9.81 m s−2 and c=3.00×108 m s−1 unless otherwise stated.
- Give non-exact numerical answers to three significant figures.
Section A: Fundamental Concepts (Questions 1–5)
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Define the term power in the context of energy transfer. [1]
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A block of mass 2.5 kg is pushed across a rough horizontal surface at a constant speed of 3.0 m s−1. If the coefficient of kinetic friction is 0.40, calculate the power delivered by the pushing force. [2]
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State the principle of conservation of energy. [1]
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A light bulb is rated at 60 W,240 V. Calculate the resistance of the filament when it is operating at its rated power. [2]
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Explain why the power output of an engine is not always equal to the rate of energy released by the fuel. [2]
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Section B: Mechanics and Energy (Questions 6–12)
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A 0.20 kg ball is dropped from a height of 5.0 m. Calculate its kinetic energy immediately before it hits the ground, assuming air resistance is negligible. [2]
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A car of mass 1200 kg accelerates from rest to 20 m s−1 in 8.0 s. Calculate the average power delivered by the engine. [3]
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A mass m is attached to a spring with spring constant k. If the spring is compressed by a distance x, express the elastic potential energy stored in terms of k and x. [1]
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A 0.50 kg block slides down a frictionless incline of angle 30∘ from rest. After sliding a distance of 2.0 m along the slope, calculate its speed. [3]
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A pump lifts 100 kg of water per minute from a well 15 m deep. Calculate the minimum power required for the pump. [3]
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A projectile is launched at an angle θ to the horizontal with velocity u. Show that the kinetic energy at the highest point of its trajectory is KE=21mu2cos2θ. [2]
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A 0.10 kg ball bounces off a hard floor. It hits the floor at 4.0 m s−1 and rebounds at 3.0 m s−1. Calculate the energy lost during the collision. [2]
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Section C: Nuclear Energy and Power Laws (Questions 13–20)
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Explain what is meant by the binding energy of a nucleus. [2]
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The mass of a 12C nucleus is 11.001 u. The mass of a proton is 1.00727 u and a neutron is 1.00866 u. Calculate the mass defect of the 12C nucleus. [2]
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Using your answer to Question 14, calculate the binding energy of the 12C nucleus in MeV. (1 u=931.5 MeV/c2) [2]
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In a nuclear fusion reaction, two light nuclei combine to form a heavier nucleus. Explain why energy is released during this process. [3]
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A variable x and a current I are related by a power law x=kIn. If x increases by a factor of 8 when I is doubled, determine the value of the constant n. [3]
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For the power law x=kIn mentioned in Question 17, describe how a graph of logx against logI can be used to find k. [3]
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A radioactive sample has an activity of 200 Bq. If each decay releases 5.0 MeV of energy, calculate the total power output of the sample in Watts. [3]
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A particle of mass m is accelerated from rest through a potential difference V. Derive an expression for its final velocity v. [3]
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