Average speed = (distance covered) / (time to cover the distance) =
(255mi) / (4.75 hr) = 53.68 miles per hour
Average velocity = (displacement) / (time)
("Displacement" is the distance and direction from the starting point
to the end point, regardless of the route taken.)
= (121 miles west) / (4.75 hours) = 25.47 miles per hour west
