stopping distance

• what is the stopping distance of a vehicle equal to?

  sum of thinking distance & braking distance
• for a given braking distance if the speed is greater what happens to the stopping distance?

  the stopping distance is greater
• what happens to the breaking distance of a car if speed doubles (in terms of kinetic energy)

  • 1/2mv2
  • doubling the speed of the car increases its kinetic energy by 4 times
  • brakes must do 4 times the amount of work to stop the car
  • since maximum braking force is constant, the car must travel 4 times further while the breaks are applied
• why would distractions increase the stopping distance?

  • stopping distance = thinking distance + braking distance
  • there is additional time before the driver applies the brakes
  • so the thinking distance will increase