The distance, s(t), in feet, traveled by a ball rolling down a ramp is given by the function s(t) = 4t^2, where t is the time, in seconds, after the ball is released. Find the ball's average velocity from a. t1 = 1 second to t2 = 2 seconds. b. t1 = 1 second to t2 = 1.5 seconds. c. t1 = 1 second to t2 = 1.01 seconds.