Question

A car moving with a uniform velocity 54kmph is brought to rest in travelling a distance of 5m What is the retardation produced by brake?

Answer 1

Initial velocity of the car.,

u = 54km/hr

= (54 x 1000)/3600 = 15 ms^-1

Final velocity of the car, v =0.

Let a be the retardation of the car. Then using the relation.

v² = u² + 2as

0² = 15² + 2a × 5

a = (-15 x 15)/(2 x 5) = 225/10 = – 22.5 ms^-2.