$\backslash$#$9)$ A ball is thrown upward with an initial speed f $48$ feet per second from the edge of a cliff $432$ feet above a river. Find its height above the water after $\backslash ($ t $\backslash )$ seconds. when does it reach its maximum height? After how many seconds does it hit the water? $($simplify your answer, which need not to be a rational number.$)$

Be sure to use words to clearly what each variable and function in your selution represents.