Atrain which is traveling at 79 mi/hr applies its brakes as it reaches point a and slows down with a constant deceleration. its decreased velocity is observed to be 60 mi/hr as it passes a point 1/2 mi beyond a. a car moving at 52 mi/hr passes point b at the same instant that the train reaches point a. in an unwise effort to beat the train to the crossing, the driver "steps on the gas." calculate the constant acceleration a that the car must have in order to beat the train to the crossing by 3.6 sec and find the velocity v of the car as it reaches the crossing.