A safety engineer investigated the sensor response times of an autonomous vehicle's emergency braking system under two different environmental conditions: Daylight and Heavy Rain.
In each test, the vehicle was released from rest down a test ramp where it accelerated at a constant rate of 6.4 m s-2. The distance, ddd (in metres), that the vehicle travelled before the emergency brake was triggered was recorded.
The results are shown in the table below.
| Condition | Trial 1 (m) | Trial 2 (m) | Trial 3 (m) | Trial 4 (m) | Trial 5 (m) | Average distance (m) |
|---|---|---|---|---|---|---|
| Daylight | 0.54 | 0.62 | 0.48 | 0.51 | 0.55 | 0.54 |
| Heavy Rain | 1.12 | 1.25 | 1.08 | 1.15 | 1.20 | 1.16 |
Calculate the average sensor response time, ttt (in seconds), for the trials in Daylight.
Use the equation:
t2=d3.2 t^2 = \frac{d}{3.2} t2=3.2dwhere d d\,d is the average distance in metres.
Give your answer to 2 significant figures.
39 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.