Fast cars

How do you stop a fast-moving object?

Motorised vehicles like cars can't rely on friction and air resistance to stop because that would take too long and be very dangerous. If a car needs to stop, the driver puts on the brakes.

The brakes push on the wheels so that there is lots of friction on the wheels, which stops them from turning.

If a car is travelling fast, it takes more force to stop it than if it's travelling slowly. A car will continue going forward whilst it's braking so, the faster it is going, thefurther it will travel before it can stop. This is why there is a speed limit on roads – so that cars go slow enough that they can stop in a short distanceif they need to.