13. An object is moving in a straight line from a fixed point. The displacement s (in metres) is given by s = -2t= + 28t + 45, t 2 0, where tis in seconds. a) Find the velocity at any time. b) What is the velocity at t=3s c) Find t when the object reaches maximum displacement. d) Find the maximum displacement reached by the object. e) What is the average velocity from t = 0 tot = 8 f) Find the acceleration at any time