Atennis ball bounces so that its initial speed straight upwards is b feet per second. its height s in feet at time t seconds is given by s = bt − 16t^2 a) find the velocity v = ds/dt at time t. b) find the time at which the height of the ball is at its maximum height. c) find the maximum height. d) make a graph of v and directly below it a graph of s as a function of time. be sure to mark the maximum of s and the beginning and end of the bounce.