8 equations. Each page has 10 real-life ramped questions with full FIFA solutions. Every equation is given on the equation sheet in the exam.
Key: C+S = Combined and Separate | S only = Separate Physics only | HT = Higher tier only
- Kinetic energy: Eₖ = ½mv² (C+S)
- Gravitational potential energy: Eₚ = mgh (C+S)
- Elastic potential energy: Eₑ = ½ke² (C+S)
- Specific heat capacity: ΔE = mcΔθ (C+S)
- Power: P = E/t (C+S)
- Power: P = W/t (C+S)
- Efficiency using energy (C+S)
- Efficiency using power (C+S)
Key definitions
Write your answer on paper first, then tap Show answer. Learn the key words – definition questions are quick marks in the exam.
1. What is a system? (C+S)
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An object or group of objects being studied.
2. Name the eight energy stores. (C+S)
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Kinetic, gravitational potential, elastic potential, thermal (internal), chemical, magnetic, electrostatic and nuclear.
3. State the principle of conservation of energy. (C+S)
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Energy can be transferred usefully, stored or dissipated, but it cannot be created or destroyed.
4. What is a closed system? (C+S)
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A system where no energy enters or leaves, so there is no net change to the total energy of the system.
5. What does “dissipated” (wasted) energy mean? (C+S)
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Energy transferred to the surroundings in a way that is not useful – usually by heating the surroundings, so it spreads out and becomes less useful.
6. What is power? What is 1 watt? (C+S)
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Power is the rate at which energy is transferred, or the rate at which work is done. 1 watt = 1 joule of energy transferred per second.
7. What is efficiency? (C+S)
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The proportion of the total input energy that is usefully transferred: efficiency = useful output energy ÷ total input energy. It has no unit and can never be more than 1 (100%).
8. What is the specific heat capacity of a substance? (C+S)
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The amount of energy required to raise the temperature of 1 kg of the substance by 1 °C.
9. What does a high thermal conductivity mean? (C+S)
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The material transfers energy by conduction at a higher rate. Materials with low thermal conductivity are good thermal insulators.
10. Give two ways of reducing unwanted energy transfers. (C+S)
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Lubrication (reduces friction between moving parts) and thermal insulation (e.g. thicker walls, loft insulation, double glazing – reduces the rate of heating the surroundings).
11. What is a renewable energy resource? Give three examples. (C+S)
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A resource that is being (or can be) replenished as it is used, e.g. solar, wind, hydroelectricity, tides, waves, geothermal, bio-fuel.
12. What is a non-renewable energy resource? Give three examples. (C+S)
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A resource that will run out because it is not replaced as fast as it is used, e.g. coal, oil, gas (fossil fuels) and nuclear fuel.
