large decelreations

• Reaction times are 0.2 to 0.9 seconds
• stopping distance = thinking distance + braking distance
• stopping distance = thinking distance + braking distance
• A driver’s reaction time can be affected by: tiredness drugs alcohol distractions
• Explain that the stopping distance of a vehicle is affected by a range of factors including:

  • mass of the vehicle
  • speed of the vehicle
  • driver’s reaction time
  • state of the vehicle’s brakes
  • state of the road
  • amount of friction between the tyre and the road surface
• The braking distance of a vehicle can be increased by:

  
  

  1. poor road and weather conditions, such as gravel, or wet or icy roads - less friction between tyres and the road
  2. poor vehicle conditions, such as worn brakes or worn tyres - less friction between brakes and
• What is thinking distance

  the distance a vehicle travels in the time it takes for the driver to apply the brakes after realising they need to stop
• What is braking distance

  Is the distance a vehicle travels in the time after the driver has applied the brake
• What increase the thinking distance when stopping you from given speed?

  Longer reaction times
• The braking distance of a vehicle can be increased by: poor vehicle conditions, such as worn brakes or worn tyres - less friction between brakes and wheels
• The braking distance of a vehicle can be increased by:

  1. more mass in the vehicle (extra passengers for example) - the braking friction has to work for a greater distance to remove the larger kinetic energy
• Why do crumple zones reduce impact


  -front and back of crumple zones crumple meaning extra time for momentum to be lost
• How to reduce damage of car crashes

  Spread change in momentum over period of time of the car because it reduces force
• If vehicle spead increases by 2 braking distance increases by 


  4
• Why do airbags reduce injuries


  -it's comperssionable so it loses momentum more slowly