A ball falls off the top of a roof 320 feet above the ground. The formula h = -16t^2 + 16t + 320 describes the height of the ball above the ground, h, in feet, t seconds after the fall begins. How long will it take the ball to strike the ground?
A parabola word problem is solved. The response received a rating of "5/5" from the student who originally posted the question.