Question

A car of mass 1330 kg is traveling at 28 m/s.  The driver applies the brakes to bring the car to rest over a distance of 79 m. Calculate the force acting on the car.

Answer 1

you could use SUVAT to work out the deceleration and then use F=ma

S= 79m U=28m/s V=0m/s A=? T=n/a

V^2 = U^2 + 2AS so 0 = 28^2 + 158A so -158A = 784

A= 4.962 (3dp)

so F = ma = 4.962 *1330 = 6599.494N (3dp)