A train which is traveling at 80 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 50 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 4 sec and find the velocity v of the car as it reaches the crossing. the train is 1 mi away from intersection going 80 mi/hr the car is 1.3 mi away from the intersection going 50 mi/hr.