Question 712033
At {{{ t = 0 }}}, 
{{{ h(0) = -16*0^2+128*0+144 }}}
{{{ h(0) = 144 }}}
which just means that the object is
{{{ 144 }}} ft above the ground
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When the object hits the ground, {{{ h = 0 }}}
{{{ h = -16*t^2+128t+144 }}}
{{{ 0 = -16*t^2+128t+144 }}}
Divide both sides by {{{ -16 }}}
{{{ t^2 - 8t - 9 = 0 }}}
{{{ ( t - 9 )*( t + 1 ) = 0 }}}
{{{ t = 9 }}}
The object hits the ground in 9 sec
The other solution is {{{ t = -1 }}} sec
which is not possible.