On a test track, a lorry is brought to rest after its driver detects a hazard. At the original speed, the distance travelled before braking starts is 18 m, and the distance travelled while braking is 48 m. For a repeat test, the lorry travels at 70% of its original speed. The driver takes the same time to react, and the lorry's mass and braking force do not change.
What is the decrease in the lorry's stopping distance?
36.12 m36.12\ \mathrm{m}36.12 m
24.48 m24.48\ \mathrm{m}24.48 m
29.88 m29.88\ \mathrm{m}29.88 m
23.52 m23.52\ \mathrm{m}23.52 m
126 exam-style questions on Edexcel GCSE Physics 2.5 Stopping and braking distances, covering 2.5.1 Stopping distance and reaction time, 2.5.2 Factors affecting stopping distance, 2.5.3 Dangers of large decelerations, and 2.5.4 Braking distance and initial speed. Each one has a worked solution and a mark scheme showing where the marks go.