Question 1178634
{{{h=378}}}

{{{378=-16t^2+30t+432}}}

{{{0=-16t^2+30t+432-378}}}

{{{0=-16t^2+30t+54}}}

{{{0 = -2 (t - 3) (8 t + 9)}}}

solutions:

{{{t=3}}}

{{{t=-9/8}}}->throw out the negative solution

The ball will be at a height of {{{378}}} feet after {{{3}}} seconds.


{{{drawing ( 600, 600, -10, 10, -10, 450,
circle(3,378,.12), locate(3,378,h(3,378)),
graph( 600, 600, -10, 10, -10, 450, -16x^2+30x+432)) }}}