If a car goes along a straight road heading west and speeds up from 25 ft/s to 60 ft/s in 5 s, calculate the acceleration.

Acceleration =

(change in speed) / (time for the change)

and

direction of the change.

Change in speed = (end speed) - (start speed) = (60 - 25) = 35 f/s

Time for the change = 5 sec

Direction of the change = west

Acceleration = 7 ft/sec² west.