A foul tip of a baseball is hit straight upward from a height of 4 feet with an initial velocity of 80 feet per second. The function s(t) = - 16t + 80t + 4 describes the ball's height above the ground, s(t), in feet, t seconds after it was hit. a. What is the instantaneous velocity of the ball 2 seconds after it was hit? 4 seconds after it was hit? b. The ball reaches its maximum height above the ground when the instantaneous velocity is zero. After how many seconds does the ball reach its maximum height? What is its maximum height? a. What is the instantaneous velocity of the ball 2 seconds after it was hit? v= feet per second