A railway train goes from one station to another moving during the first part of the journey with uniform acceleration a; when steam is shut off and the brakes are applied, it moves with retardation a' . If s be the distance between the stations, show that the time the train takes is 2s...

A railway train goes from one station to another moving during the first part of the journey with uniform acceleration a; when steam is shut off and the brakes are applied, it moves with retardation a' . If s be the distance between the stations, show that the time the train takes is 2s(a+a′)aa′