During halftime of a basketball ​game, a sling shot launches​ T-shirts at the crowd. A​ T-shirt is launched with an initial upward velocity of 78 feet per second. The hight of the t-shirt (h) in feet after t seconds is given by the function h=-16t^2+78t+5. How long will it take the​ T-shirt to reach its maximum​ height? What is the maximum​ height? What is its maximum height?