The (non-conservative) force propelling a 1.90 x 103-kg car up a mountain road does 6.70 x 106 J of work on the car. The car starts from rest at sea level and has a speed of 20.0 m/s at an altitude of 1.80 x 102 m above sea level. Obtain the work done on the car by the combined forces of friction and air resistance, both of which are non-conservative forces.