Starting from rest, a truck travels in a straight line for 9.0 s with a uniform acceleration of +1.5 m/s2. The driver then applies the brakes for 2.0 s, causing a uniform acceleration of -3.0 m/s2 over that time.
(a) What is the truck's speed at the end of the braking period? m/s
(b) What is the total distance traveled by the truck (from the point where it started at rest to the end of the braking period)?