Question

a car is moving with a velocity 20 metre per second when brake is applied to it stops in 5 seconds find its displacement after the break applied

Answer 1

When the brake is applied the car comes to rest. Thus the final velocity is 0m/s.

We can get the deceleration of the car by:

(0 - 20) ÷ 5 = - 4m/s²

Using the equation of motion we have :

S = ut - 0.5at²

U = 20m/s

t = 5

a = 4m/s²

S = 100 - 50 = 50m

Displacement is thus 50m