A minibus undergoes a controlled braking test on a level, dry test track. The stopping distance is measured from the moment a warning light is switched on until the minibus comes to rest.
The minibus has a mass of 3000 kg and an initial speed of 16 m/s. The test driver's reaction time is 0.75 s.
| condition of brakes | test information |
|---|---|
| worn brakes | measured stopping distance =44 m |
| repaired brakes | mean resultant braking force =16000 N |
To pass the safety inspection, the stopping distance with the repaired brakes must not exceed 38 m.
Calculate the mean resultant braking force produced by the worn brakes. Show your working.
Calculate the stopping distance of the minibus with the repaired brakes. Use your answer to state whether the minibus passes the safety inspection.
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.