Weight and friction
You should know some of the factors affecting the stopping distance of a car.
It takes a certain amount of time for a driver to react to a hazard and start applying the brakes. During this time, the car is still moving. The faster the car is travelling, the greater this thinking distance will be.
The thinking distance will also increase if the driver's reactions are slower because they are:
The braking distance is the distance the car travels from where the brakes are first applied to where the car stops. If the braking force is too great, the tyres may not grip the road sufficiently and the car may skid. The faster the car is travelling, the greater the braking distance will be.
The braking distance will also increase if:
The stopping distance is the thinking distance added to the braking distance. The graph shows some typical stopping distances.
Watch this video to see a summary of how gravity and friction forces affect motion.