Question

A car is moving with a velocity 20m per s when brakes are spoiled to retard at a rate of 2m per s. What will be the velocity of the car after 5 s of applying brakes

Answer 1

Initial velocity u = 20 m/s

Deceleration produced by braking a = - 2 m/s²

Time for which brakes are applied t = 5 s

Velocity at the end of 5 s braking can be found using the relation; v = u + a t

v = 20 +(- 2 × 5)
= 20 - 10
v = 10 m/s.

So after 5 s of braking the car shall have a velocity = 10 m/s.