Solve the problem. Round to the nearest tenth, if necessary.
-A rock falls from a tower that is $63.7 \mathrm{~m}$ high. As it is falling, its height is given by the formula $\mathrm{h}=63.7-4.9 \mathrm{t}^{2}$. How many seconds will it take for the rock to hit the ground $(\mathrm{h}=0)$ ?
A) $8 \mathrm{sec}$
B) $7.7 \mathrm{sec}$
C) $3.6 \mathrm{sec}$
D) $828.1 \mathrm{sec}$

Question

Quizplus · Accepted Answer

To find the time it takes for the rock to hit the ground, set $h = 0$ and solve for $t$: $0 = 63.7 - 4.9t^2$. Rearranging gives $4.9t^2 = 63.7$, and solving for $t$ gives $t = \sqrt{\frac{63.7}{4.9}}$, which is approximately $3.6$ seconds.

Solve the Problem 63.7 m63.7 \mathrm{~m}63.7 m High as It Is Falling, Its Height Is Given by

Solve the Problem $63.7 \mathrm{~m}$ High as It Is Falling, Its Height Is Given by