A ball is thrown upward from the top of a 40-foot-high building at a speed of 80 feet per second. The ball’s height above ground can be modeled by the equation: H(t)=-16t²+80t+40.


a. When does the ball reach the maximum height? (10 points)
b. What is the maximum height of the ball? (10 points)
c. When does the ball hit the ground? (10 points)