A person standing close to the edge on top of a 64-foot building throws a ball vertically upward. The quadratic function h ( t ) = − 16 t 2 + 48 t + 64 models the ball's height above the ground, h ( t ) , in feet, t seconds after it was thrown. a) What is the maximum height of the ball? feet b) How many seconds does it take until the ball hits the ground? feet