posted by seanso .
A truck on a straight road starts from rest and accelerates at 2.0 m/s2 until it reaches a speed of 20 m/s. Then the truck travels for 20 s at constant speed until the brakes are applied, stopping the truck in a uniform manner in an additional 5.0 s.
(a) How long is the truck in motion?
(b) What is the average velocity of the truck during the motion described?