# Forces and braking (P2.1.3)

This card is aimed at all levels (foundation and higher). It easy easy to larn and explained to the required detail you would be expected to know. You may wish to shorten the notes further. It is relevent to the September 2011 P2.1.3.

HideShow resource information
• Created by: Quaid
• Created on: 18-12-12 15:51

## Forces and braking (P2.1.3)

a) When a vehicle travels at a steady speed the resistive forces balance the driving force. (You should also know this is mostly caused by air resistance).

b) The greater the speed of a vehicle the greater the braking force needed to stop it in a certain distance.

c) The stopping distance of a vehicle 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). (A.K.A:  stopping distance= thinking distance+ braking distance).

d) A driver’s reaction time can be affected by tiredness, drugs and alcohol. (You should also know that ditractions affect the drivers ability to react).

1 of 2

## Forces and braking (P2.1.3) (2)

e) When the brakes of a vehicle are applied, work done by the friction force between the brakes and the wheel reduces the kinetic energy of the vehicle and the temperature of the brakes increase.

Key words:

thinking distance

braking distance

balance

sum of

tirdness, drugs, alcohol

friction force

2 of 2