A train which is traveling at 80 mph applies its brakes as it reaches point A and slows down with a constant deceleration. Its decreased velocity is observed to be 60 mph as it passes a point 1/2 miles beyonds A. A car moving at 50 mph 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 cart MUST have in order to beat the train to the crossing by 4 seconds and find the velocity v of the car as it reaches the crossing. Distance from train to intersection = 1 mile Distance from car to intersection = 1.3 miles.