Forces and braking

• Define 'thinking distance'

  The distance a vehicle travels in the time it takes for the driver to apply their brakes after realising they need to stop
• Define 'braking distance'

  The distance a vehicle travels in the time after the driver has applied the brake
• Longer reaction times increase...

  The thinking distance when stopping from a given speed
• The braking distance of a vehicle can be affected by:

  • Poor road and weather conditions, such as wet or icy roads
  • Poor vehicle conditions, such as worn brakes or tyres
• What happens when a force is applied to the brakes of a vehicle?

  There is work done by the friction between the brakes and the wheel, which reduces the kinetic energy of the vehicle, slowing it down and causing the temperature of the brakes to increase.
• The faster a vehicle travels..

  The greater the braking force needed to stop it in a certain distance
• A greater braking force produces a..

  Greater deceleration
• Why is the thinking distance proportional to the starting speed?

  As the reaction time is taken as a constant. However, the braking distance increases four times each time the starting speed doubles