one more doubt.its 4m the same textbook.page no 60.q no 22.the question is as follows-
A train starts from rest at a station,accelerates uniformly to its maximum speed 15m/s,travels at this speed for a time,and then decelerates uniformly to rest at the next station.the distance from station to station is 1260m,and the time spent is three-quarters of the total journey time.
(a)iilustrate this information on a velocity time graph.
(b) By using this graph,or otherwise find the total journey time.
(c) Given also that the magnitude of the deceleration is twice the magnitude of the acceleration find in m s-2,the magnitude of the acceleration.