A truck on a straight road starts from rest, accelerating at 2.0m/s2 until it reaches a speed of 20.0m/s. then the truck travels for 20s at constant speed until the brakes are applied, stopping the truck in a uniform manner in an additional 5s. (a) How long is the truck in motion? (b) What is the total distance travelled by the truck? (c) What is the average velocity of the truck for the motion described?