2. An object's height above the ground at time i is given by the function y = s(1) = 3', where y is measured in feet and t is measured in seconds. Round final answers to four decimal places and include units. a) Find the average velocity of the object over the time interval [1,1.5]. That is, find the average velocity from 1 second until 1.5 seconds. b) Find the instantaneous velocity of the object when t=1. (You may use any method we 've studied for this part.)