Two trains, one traveling at 64.00 km/h and the other at 128.00 km/h, are headed toward one another along a straight, level track.

Two trains, one traveling at 64.00 km/h and the other at 128.00 km/h, are headed toward one another along a straight, level track. When they are 711 m apart, each engineer sees the other's train and applies the brakes. The brakes decelerate each train at the rate of 1.0 m/s2. What distance do the trains need to allow between them to stop at this acceleration? What acceleration do the two trains need to have to stop exactly in a distance of 711 m?