Question

A car travelling at a speed of 30 km/h is brought to rest in a distance of 8 m by applying brakes.If the same car is moving at a speed of 60km/h then it can be brought to rest with same brakes in

Answer 1

Stopping distance s =
$mu { }^{2} \div 2 \: force$
here u =30km/h
s = 8m
u'=2(30) which is 60km/h given in question
now s' becomes
$n {}^{2} u$
new stopping distance s' will be
$2 {}^{2} \times 8$
4(8) = 32m