1. The problem statement, all variables and given/known data a bus starts from rest and accelerating at 1.5m per second squared until it reaches a velocity of 9m/s.The bus continues at this velocity and then decelerates at -2m per second squared until it comes to a stop. 400m from its starting point. How much time did the bus take to cover the 400 m? 2. Relevant equations s =vt, v=u+at, s= ut+ 1/2 * at^2, v^2= u^2 + 2as 3. The attempt at a solution intially found out the time travelled until it reaches 9m/s. so starting from rest, u=0, substituting in 2nd eq. I got t= 9sec. After this I am totally confused. I found out the initial distance travelled, and final diatance travelled . I know somewhere I am doing wrong. Please help me solving this problem.