Problem 2: An elevator starts at rest on the ground floor. The elevator moves so that its acceleration is shown
as a function of time below.

(a) Is the elevator moving upward, moving downward, or at rest at time = 12 seconds? If the elevator is
moving, state its speed. In any case, explain your reasoning.
(b) Is the elevator moving upward, moving downward, or at rest at time t 22 seconds? If
the elevator is
moving, state its speed. In any case, explain your reasoning.