A ball is thrown straight up from the top of a building that is 280 feet high with an initial velocity of 48 ft/s. The height of
the object can be modeled by the equation s(t)=−16t2+48t+280. In two or more complete sentences explain how to determine the time(s) the ball is higher than the building in interval notation. Then, determine the time.
First find the time that the ball is level with the top of the building on its descent. You can do this by solving 280 = -16^2 + 48t + 280 for t. This gives t = 3 seconds .
Then when the ball reaches the ground the time t is obtained by solving 0 = -16t^2 + 48t + 280 This gives t = 5.94
