A delivery van is tested on a straight test track. In one run a test driver brakes when a warning light comes on; in a second run an automatic braking system responds to the same warning light. The van, its load and the track surface are the same for both runs. The measurements are recorded below.
| Quantity | Measurement |
|---|---|
| Speed when the warning light comes on | 24 m/s |
| Distance travelled after the brakes engage | 45 m |
| Driver's reaction time | 0.75 s |
| Automatic system delay | 0.25 s |
| Position of marker P from the warning point | 55 m |
| Position of marker Q from the warning point | 65 m |
Which statement is correct?
With the driver, the van stops beyond marker Q; with the automatic system, it stops before marker P.
With the driver, the van stops between markers P and Q; with the automatic system, it stops between markers P and Q.
With the driver, the van stops before marker P; with the automatic system, it stops before marker P.
With the driver, the van stops between markers P and Q; with the automatic system, it stops before marker P.
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.