A motorcycle and a minivan are at rest, side by side, at a stoplight. A pickup truck is approaching the intersection from behind the motorcycle and minivan, at 20 m/s. At the instant the traffic light turns green, t=0s, the pickup truck is 140m behind the minivan. When the light turns green, the motorcycle accelerates at 4 m/s^2 for 5 seconds, while the minivan accelerates at 2m/s^2 for ten seconds. Once each vehicle stops accelerating, it maintains a constant speed.

(a) determine the speed of the motorcycle from the perspective of a passenger of the truck. (i) at t=2s