Headings Forces and
Motion Search Questions 
Braking Distance of a Car - Conditions.
The braking force which brings a car to a stop depends on friction.
When the brakes
are applied the car loses kinetic
energy (it slows down).
The kinetic energy
which is lost is transferred
to the brakes and the wheels
which both get hotter.
If the brakes are not seriously worn or malfunctioning,
then friction here is very good because of modern brake design and
materials.
The most
important friction occurs between the tyres and the road
surface.
If the road is wet or icy, then friction is reduced and the car
will take longer to stop
or the tyres will slip (skid).
The tread on the tyre makes water on
the
surface of the road
go up into the grooves and then the water is thrown
out sideways to get it out from under the
tyre. If the tread is not deep
enough
the tyre can not remove surface
water quickly
and the tyre will ride up on top
of the
water and loose contact with the
road (called aquaplaning).
Headings Forces and
Motion Search Questions
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