Listen to this.
lets talk about work.
Work is not only equal to force times distance, but is also equivalent to the change in kinetic energy.
For instance, if a car of mass m is traveling 10 m/s and comes to a stop in 15 m, its very easy to find the work.
Work=Change in Ke=((1/2)m(10)^2)- ((1/2)m(0)^2)=50m
This means that the breaks in this car must do 50m j of work to stop the car.