Question

What is the radius of a hemisphere with a volume of 920 ft^3 to the nearest tenth of a foot?

Answer 1

7.6 ft

Explanation:

The volume of a sphere is

V = 4/3 pi r^3

A hemisphere is 1/2 of a sphere

V = 1/2 (4/3 pi r^3)

V = 2/3 pi r^3

920 = 2/3 pi r^3

Multiply each side by 3/2

920 * 3/2 = 3/2 * 2/3 pi r^3

1380 = pi r^3

Divide each side by pi

1380/pi = pi r^3 / pi

1380/ pi = r^3

Using pi as 3.14

1380/3.14 = r^3

439.4904459= r^3

Taking the cube root of each side

(439.4904459)^(1/3)= r^3^(1/3)

7.602967711=r

To the nearest tenth

7.6 = r

Answer 2

radius=7.6ft

Answer:

Solution given:

radius [r]=?

Volume of hemisphere=920ft³

⅔*πr³=920

r³=920*3/(2π)

r³=439.267

r=
`\sqrt[3]{439.267}=7.6ft`