Not exactly sure what you are asking.Originally Posted bybobby77

v(1) = 26 mph

v(3) = 28 mph

So the car is moving between 26 and 28 mph during the times t = 1 hr and t = 3 hr.

Was that what you were looking for? The only other thing I can think of is that you are looking for an average speed which would be since v is a linear function of t.

-Dan