Chapter 9.3, Problem 6STP

For Exercises 1-7, choose the correct letter.

What is the radius of a sphere whose surface area is 100 square centimetres? Use the formula for determining the surface area of a sphere, $s=4\pi r^2$, and 3.14 for $\pi$.

Round your answer to the nearest hundredth.

F. 2.82 cm

G. 5 cm

H. 5.64 cm

I. 125,600 cm

To determine

To find: The radius of a sphere.

Answer to Problem 6STP

The radius of a sphere $=2.82\text{ cm}$ .

Correct letter

(F)

Explanation of Solution

Given information: Surface area of a sphere is $100\text{ square centimeters}$ .

Surface area of a sphere, $S=4\pi r^2$ .

Given surface area of a sphere is $100\text{ square centimeters}$ .

Then

  $\begin{array}{l}4\pi r^2=100\\ r^2=\frac{100}{4\pi }\\ r^2=7.96\\ r=2.82\text{ cm}\end{array}$