Stopping Distance
1) THINKING DISTANCE
Consider a car driving down a road at a constant speed. Suddenly, a boy runs out into the road. The first thing that happens is that the driver must REACT. This takes TIME. This time is called REACTION TIME or THINKING TIME. The car is still moving at this time. The distance the car moves in this time is called REACTION DISTANCE or THINKING DISTANCE.
*Factors that affect thinking distance include:
- Tired/drunk driver
- Driver who has had consumption of drugs
2) BRAKING DISTANCE
When moving, a car has KINETIC ENERGY (KE). The KE is transferred by the brakes into HEAT/THERMOL ENERGY. This transformation is the work done by the brakes.
**If you double your speed, you will quadruple your breaking distance**
*Factors that affect braking distance include:
- Wet/Icy road (causing brakes to have less friction)
- Worn-out tires (less friction and grip on road’s surface)
- Overloaded car (too many people inside)
After the thinking time, the brakes are now applied and the car starts to brake. The distance it now takes for the car to brake to a stop is the BRAKING DISTANCE.
*Factors that affect braking distance include:
- Wet/Icy road (causing brakes to have less friction)
- Worn-out tires (less friction and grip on road’s surface)
- Overloaded car (too many people inside)
After the thinking time, the brakes are now applied and the car starts to brake. The distance it now takes for the car to brake to a stop is the BRAKING DISTANCE.