Thinking distance, braking distance and stopping distance
An investigation was carried out to see how the stopping distance of a car changes when it’s
travelling at different velocities. The results of the investigation when the car was moving at 18m/s
are shown on the velocity-time graph below.
20
velocity
(m/s)
10
0
0
1
2
1
0
3
1
0
0
0
0
Time (seconds)
The distance travelled by a vehicle whilst a driver reacts to a stimulus is known as the thinking
distance. This distance can be calculated by working out the area under the graph. In this example,
the thinking distance was 9m.
1. Write a definition for braking distance (2 marks)
2.
Use this graph to calculate the braking distance (2 marks)
3. Calculate the stopping distance (1 mark)
A second investigation recorded the results for the car when it was moving at 22m/s at the
moment the driver saw the stimulus. These results are recorded in the table below
Time (seconds)
0.00
0.50
1.00
1.50
2.00
2.50
3.00
4.
Velocity (m/s)
22.0
22.0
17.8
13.0
9.0
4.6
0.0
Plot these results onto the graph (2 marks)
5. Calculate how much the thinking distance, the braking distance and the stopping distance
increased when the velocity went from 18m/s to 22m/s (3 marks)