The magnitude of acceleration is (change in speed) / (time for the change).
Change in speed = (speed at the end) - (speed at the beginning) =
(16 m/s) - (0) = 16 m/s .
Time for the change = 4 s .
Magnitude of acceleration = (16 m/s) / (4 s) = 4 m/s per sec = 4 m/s² .
