AQA GCSE Physics Physics Paper 2 (Foundation), June 2023: Question 2

✅ Correct Answers

• 1. kinetic
• 2. thermal

💡 Key Knowledge

• When a vehicle slows down, its speed decreases, meaning its kinetic energy store decreases.
• Friction between the brake pads and wheels does work, dissipating energy into the surroundings as thermal energy (heat).

✅ Correct Answers

The (minimum) braking distance increases with increasing speed (allow positive correlation).

🧠 Exam Technique

When describing a graph that curves upwards, avoid saying "it goes up faster." Use precise scientific terminology like "increases at an increasing rate" or state clearly that there is a positive correlation.

✅ Correct Answers

When the road becomes icy, the braking distance increases .

💡 Key Knowledge

Icy or wet roads reduce friction between the tyres and the road surface, meaning the car takes longer and a greater distance to stop.

📐 Calculation Steps

1. Find change in velocity: 12.5 - 5.0 = 7.5 m/s
2. Rearrange/Substitute into equation: time taken = 7.5 / 0.25
3. Calculate final value: 30 s

Final Answer: Time taken = 30 s

❌ Common Calculation Traps

• Forgetting to calculate the change in velocity first and mistakenly using 12.5 directly.
• Failing to include the correct unit (seconds / s) on the answer line if not pre-printed.

📐 Calculation Steps

1. Identify values: Mass = 1600 kg, Deceleration = 0.25 m/s²
2. Substitute into equation: resultant force = 1600 × 0.25
3. Calculate final value: 400 N

Final Answer: Resultant force = 400 N

💡 Key Knowledge

This is a direct application of Newton's Second Law: F = m × a (Force = mass × acceleration).

✅ Correct Answers

Tick box: Initial height of the ruler above the person's hand

🧠 Exam Technique

A control variable is something that must be kept constant so it does not affect the dependent variable. If the starting height of the ruler changed, it would alter the distance the ruler falls independently of the person's reaction time.

✅ Correct Answers

There will be more variation in distances / Reaction times for individuals vary / The three students tested are not typical of the whole class.

💡 Key Knowledge

Small sample sizes do not represent a wider population accurately. Testing only three people means anomalies have a huge impact on the mean.

✅ Correct Answers

• 1. Carry out the experiment whilst listening to music.
• 2. Repeat without listening to music (and compare the results).

🧠 Exam Technique

When asked how to modify an experiment to test a new factor, always state clearly: what you change (listening to music vs. silence), what you measure (distance ruler falls), and what you keep the same (same person, same starting height) to ensure a fair test.