A ball is thrown upward from the top of a building 240 feet tall. The height of the ball is described by the function $h(t) = - 16 t^2 +22 t + 240$, where $t$ is in seconds and $t = 0$ corresponds to the moment the ball is thrown.

a) Determine for what value of $t$ the ball reaches the maximum height and determine this maximum height.

$t =$ and maximum height =

b) Determine when the ball reaches the ground.

$t =$