A car of mass 1000kg travels with a velocity 45km/h on a rough road and it is brought to a rest after 10s. What is the force exerted on the car?

Answer 1

Vo = 45000/3600s = 12.5 m/s.

V = Vo + a*t = 0,
12.5 + a*10 = 0,
a = -1.25 m/s^2.

F = M*a =

Answer 2

The force opposes the motion; therefore, the force will be negative.