Acar accelerates at an average rate of 2.5 m/s2. how long will it take for the car to speed up from 35.5 m/s to 45.5 m/s? (this is your change in acceleration = 45.5 m/s - 35.5 m/s.) * to do this problem, you will rearrange the acceleration equation to give you: time = change in speed/ average rate of acceleration. remember, you are trying to find time.*