Answer
549 feet
Work Step by Step
We are given in Example 5 that the height of an object at t seconds can be found by the equation $P(t)=-16t^{2}+1125$. To find the height at $t=6$ seconds, we must find the value of $P(6)$.
$P(6)=-16(6^{2})+1125=-16\times36+1125=-576+1125=549$ feet