GCSE Physics: Energy — Deep Revision Workbook

Inside GCSE Physics: Energy — Deep Revision Workbook

name energy stores and describe transfers, calculate kinetic, gravitational and elastic energy, work through specific heat capacity E = mcΔθ and rearrange it, calculate power P = E/t, then master conservation, dissipation, efficiency = useful ÷ total, reducing unwanted transfers and renewable and non-renewable energy resources, before a full exam-style 6-mark question. About 45 minutes.

Learning objectives

• energy stores and transfers — kinetic, gravitational potential, elastic potential, thermal, chemical and nuclear stores, and transfers by heating, waves, electrically and mechanically;
• energy calculations — kinetic energy Ek = ½mv², gravitational PE = mgh (g = 9.8 N/kg) and elastic PE = ½ke²;
• heating and power — specific heat capacity E = mcΔθ, rearranging it for mass and temperature change, and power P = E/t in watts;
• conservation and efficiency — energy conservation, dissipation, efficiency = useful ÷ total × 100%, and reducing unwanted transfers by insulation and lubrication;
• energy resources — renewable resources (wind, solar, hydro, tidal) and non-renewable fossil fuels (coal, oil, gas), and a full exam-style 6-mark question.

Activities in this book

1. Section 1 — Energy Stores & Transfers

   energy is never made or destroyed — it is stored and transferred. Learn the stores: kinetic (movement), gravitational potential (height), elastic potential (stretch or squash), thermal (hot objects), chemical (fuels, food, batteries) and nuclear (in the nucleus). Energy is transferred by heating, by waves, electrically or mechanically (by a force doing work).

2. Section 2 — Kinetic, Gravitational & Elastic Energy

   learn the three equations. Kinetic energy Ek = ½mv² (square the speed before halving). Gravitational PE = mgh, with g = 9.8 N/kg. Elastic PE = ½ke², where k is the spring constant and e is the extension. Show your working and give the unit joules (J).

3. Section 3 — Specific Heat Capacity & Power

   to warm something up, use E = mcΔθ: energy = mass × specific heat capacity × temperature change. Rearrange it to find any missing value: m = E ÷ (cΔθ), or Δθ = E ÷ (mc). Power is the rate of transferring energy: P = E/t in watts (W), where 1 W = 1 J/s; rearranged, E = P × t.

4. Section 4 — Conservation, Efficiency & Resources

   energy is always conserved, but some is dissipated (wasted) to the surroundings, usually as heat. Efficiency = useful output ÷ total input (× 100%). We reduce unwanted transfers with insulation (traps heat) and lubrication (cuts friction). Energy resources are renewable (wind, solar, hydro, tidal) or non-renewable (coal, oil, gas — the fossil fuels — and nuclear).

5. Section 5 — Extended Exam-Style 6-Marker

   a 6-mark question rewards clear, linked physics. Plan first: name the energy stores at the start, during and end, describe each transfer, and use the idea that energy is conserved but some is dissipated. Where you can, name an equation or give a number. Write in full sentences and use the correct key terms.

Suggestions for teaching

• Stores first, then transfers. Make sure learners can name every energy store before describing how energy moves between them — it underpins every calculation.
• Drill the three energy equations. Practise Ek = ½mv² (square the speed first), GPE = mgh with g = 9.8, and elastic PE = ½ke² until they are automatic.
• Rearrange with confidence. Show E = mcΔθ solved for m and for Δθ, and P = E/t solved for E, so the triangle is second nature.
• Model efficiency. Show useful ÷ total × 100%, and stress that the “lost” energy is dissipated to the surroundings, not destroyed.
• Practise the 6-marker. Teach learners to plan marking points (stores, transfer, dissipation, a supporting calculation) before writing full sentences.