Question

On Your Own

1) A sphere has a radius of 7 cm. What is the volume?
round your answer to the
nearest cubic centimeter.
Like example 1
4
2) A sphere has a volume of 72π in³. What is the radius?
round to the nearest tenth
of an inch.
Like example 3

Answer 1

1) 616
`cm^(3)`

2) 4.2in

Explanation:

1)

the volume of a sphere is
`4\pi r^(2)`

so you plug in the radius for r, and that is 4*
`\pi`*
`7^(2)` = 196
`\pi`= approximately 615.75216

round this to the nearest cubic centimeter and its 616

2)

the volume of a sphere is
`4\pi r^(2)`

so
`4\pi r^(2)`=V and V=72
`\pi`

72
`\pi`/4
`\pi`=
`4\pi r^(2)`/4
`\pi`

`√(18) =\sqrt{r^(2) }`

4.24264=r

round this to the nearest tenth of an inch and r = 4.2