Physics (AS & A Level) · May / June 2019 · Paper 11 · Question 5

The speed shown on a car's speedometer is proportional to the rate of rotation of the tyres. The variation of the diameter of a tyre as it wears introduces an error in the speed shown on the speedometer. A car has new tyres of diameter 600 mm. The speedometer is accurately calibrated for this diameter. The tyres wear as shown, with 6 mm of material being removed from the outer surface. What is the error in the speed shown on the speedometer after this wear has taken place?

1. AThe speed shown is too high by 1%.
2. BThe speed shown is too high by 2%.
3. CThe speed shown is too low by 1%.
4. DThe speed shown is too low by 2%.

As printed in the paper