Question

A motor car is moving with a velocity of 108 km per hour and it take 4 second to stop after the brake are applied? Calculate the force exerted by the brake on the motor car if mass along with the passenger is 1000kg?

Answer 1

Answer:

F =  - 7500 N

Explanation:

u = 108 mk/h = 108/3.6 m/s = 30 m/s

v= 0 m/s      &    t = 4 s        & m  = 1000 kg

F = ma = m x v - u / t

      =  1000 (0 - 30) / 4

       = 250 x -30

     F =  - 7500 N  -ve sigm is due to applying brakes ( deceleration)