Solve the problem.
-A rock falls from a tower that is 464 feet high. As it is falling, its height is given by the formula $h = 464 - 16 t ^ { 2 }$ How many seconds (in tenths) will it take for the rock to hit the ground (h = 0)?
A) 5.4 sec
B) 21.2 sec
C) 13,456 sec
D) 21.5 sec

Question

Quizplus · Accepted Answer

To find the time it takes for the rock to hit the ground, set $h = 0$ and solve for $t$: $0 = 464 - 16t^2$. Rearranging gives $16t^2 = 464$, and solving for $t$ gives $t^2 = 29$, so $t = \sqrt{29}$, which is approximately 5.4 seconds.

Solve the Problem h=464−16t2h = 464 - 16 t ^ { 2 }h=464−16t2

Solve the Problem $h = 464 - 16 t ^ { 2 }$