Suppose the distance s (in feet) covered by a car moving along a straight road after t seconds is given by the function S = f(t) = 3t + 13t. a. Find the average velocity of the object over the time period [1,2]. Round your answer to nearest 1 decimal place. A/ b. Find the instantaneous velocity when t=35 second. Round your answer to nearest 1 decimal place. A/