Chapter 10.5, Problem 5STP

For Exercises 1-5, choose the correct letter.

The function $t=\sqrt{\frac{d}{16}}$ models the time tin seconds that an object has been falling after the object has fallen d feet. When will the time be more than or equal to 1 minute?

A. $d\ge 16ft$

B. $d\ge 225ft$

C. $d\ge 3600ft$

D. $d\ge 57,600ft$

To determine

To find: that when the time be more than or equal to $1$ .

Answer to Problem 5STP

when $d\ge 16$ the time will be more than or equal to $1$ .

Explanation of Solution

Given information:

The function is $t=\sqrt{\frac{d}{16}}$ .

Calculation: to find that when the time be more than or equal to $1$ ,

  $\begin{array}{l}t\ge 1\\ \sqrt{\frac{d}{16}}\ge 1\text{ [substitute]}\\ \frac{d}{16}\ge 1\text{ [square]}\\ d\ge 16\text{ [multiply]}\end{array}$

Thus, when $d\ge 16$ the time will be more than or equal to $1$ .