A council plans to reduce the speed limit on the road outside a school from 13 m/s to 9 m/s.
A typical driver has a reaction time of 0.70 s. When braking, a typical car decelerates at 6.5 m/s2.
A child runs into the road 15 m in front of a car.
Evaluate whether reducing the speed limit makes the road safer for the child.
Use calculations of stopping distance in your answer. Use the Equation Sheet.
50 exam-style questions on OCR GCSE Physics 8.1 Physics on the move, covering 8.1.1 Typical everyday speeds, 8.1.2 Typical everyday accelerations, 8.1.3 Ratios, units and rates on the road, 8.1.4 Human reaction times, 8.1.5 Factors affecting stopping distance, 8.1.6 Stopping distances at different speeds, 8.1.7 Dangers of large decelerations, 8.1.8 Estimating forces in road situations, and 8.1.9 Estimating the effects of large accelerations. Each one has a worked solution and a mark scheme showing where the marks go.