FRICTION AND BRAKING
3 marks · EasyDescribe how the condition of the tyres and the road surface affect the braking distance of a car. Explain your answer.
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Braking distance increases if the tyres are worn or the road is wet or slippery, because there is less friction between the tyres and the road. More friction from good tyre tread and a dry road leads to a shorter braking distance.
Also accept: If tyres are in poor condition or the road is wet, the car takes longer to stop. Good tyres and a dry road mean the car stops more quickly.
Common mistakes: Not explaining that friction is reduced with worn tyres or wet roads.
Show mark scheme and worked solution
Marking points
B1 · 1 mark · States that worn tyres or poor road condition increase braking distance.
B2 · 1 mark · Explains that reduced friction is the cause.
B3 · 1 mark · States that good tread and a dry road increase friction and decrease braking distance.
Worked solution
If the tyres are worn or the road is wet or icy, there is less friction between the tyres and the road. Less friction means the car cannot slow down as quickly, so the braking distance becomes longer. Good tyre tread and a dry road provide more friction, helping the car to stop in a shorter distance.