AQA GCSE Physics Physics Paper 1 (Foundation), November 2021: Question 7

✅ Correct Answers

• Decreasing energy store: gravitational potential
• Increasing energy store: kinetic

💡 Key Knowledge

As an object falls, vertical height decreases, meaning gravitational potential energy is transferred into movement energy (kinetic energy).

❌ Common Errors

Swapping the order or choosing incorrect stores from the box (like elastic potential or nuclear) which do not apply to a simple free-fall scenario.

✅ Correct Answer

kinetic energy = 0.5 × mass × speed²
or Eₖ = ½mv²

🧠 Exam Technique

Learn standard physics equations word-for-word or use universally accepted standard symbols with a clear definition if required. Always write out the formula before substituting numbers in later calculation questions.

✅ Correct Answer

Mass = 70 kg

📐 Step-by-Step Calculation

1. Write equation: Eₖ = 0.5 × m × v²
2. Substitute values: 5040 = 0.5 × m × 12²
3. Simplify powers: 5040 = 0.5 × m × 144
   5040 = 72 × m
4. Rearrange: m = 5040 / 72
5. Calculate final answer: m = 70 kg

❌ Common Calculation Traps

• Forgetting to square the speed: Calculating 0.5 × 12 instead of 12² (= 144) is a very common student error.
• Incorrect rearrangement: Dividing by the wrong term or failing to isolate mass properly.

✅ Correct Answer

Tick: The thermal energy increases.

💡 Key Knowledge

When the diver hits the water, work is done against resistance. Mechanical energy is dissipated to the surroundings as sound and thermal energy, slightly increasing the thermal energy of the water.