Question

A motor car is moving with a velocity of 108 km/h and it takes 4s to stop after the beakers are applied. Calculate the force exerted by the brakes on the motorcar if its mass along with the passengers is 1000 kg.

Answer 1

velocity V=108km/h=108x1000/60x60s=30m/s
time t=4s
mass m =1000kg
using V=u +at
30=0=a4
a=30/4
a =7.5m/Square. sec
force F =ma
F=1000x7.5
F=7500N