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

Explanation

Here, `u=108km//h = (108xx1000m)/(60xx60s)=30m//s, t = 4s, v=0,F=?, m=1000kg`
`F=ma=(m(v-u))/t = (1000(0-3))/4= -7500N`
Negative sign indicates that the force is opposing or braking.