A road sweeper is travelling at 43.2 km/h. A temporary traffic signal changes to red when the road sweeper is 23 m from the stop line. The braking distance under these conditions is 14 m. The driver's reaction time is 0.78 s. A speed of 1 m/s is equivalent to 3.6 km/h.
Calculate the greatest reaction time that would allow the road sweeper to stop at or before the stop line. State whether this driver will stop at or before the stop line.
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.