A car is traveling along a highway at 90.0km/h. The driver spots a stalled car and some traffic congestion on the road ahead, and applies the brakes. The braking action causes a frictional force of 8.4x10^3N to act on the 1050kg car. a) what is the acceleration of the car when the brakes are applied? b) how long does it take for the car to stop? c) how far does the car travel while braking