Forces and Braking

Question 1

What is the stopping distance of a vehicle?

Answer 1

It is the sum of the distance the vehicle travels during the driver’s reaction time (thinking distance) and the distance it travels under the braking force (braking distance).

Question 2

For a given braking force, how does stopping distance change with speed of the vehicle?

Answer 2

For a given braking force the greater the speed of the vehicle, the greater the stopping distance.

Question 3

What is a typical human reaction time?

Answer 3

0.2-0.9s

Question 4

What can affect a driver’s reaction time?

Answer 4

Tiredness, drugs, alcohol and distractions.

Question 5

How can a human reaction time be measured?

Answer 5

There are some computer programs which measure reaction times. Another method is to drop a ruler and compare where on the ruler you caught it to where you dropped it from.