A passenger car has a speed of 16.8 m/s when it reaches point A. The average frictional force between the car and the track from point A to B is 250N. At point B in addition to this frictional force, the car's breaks are applied so that the passenger car stops at point B.
Question: What additional force that must be applied by the breaks between point A and B in order to stop the car at point B?
The Attempt at a Solution
EK is all I know.