Question

If the radius of a sphere increases from 3 feet to 9 feet, by how many cubic feet does the volume of the sphere increase? 967 ft3 A 1087 ft3 936 ft 0

Answer 1

The volume of a sphere is given by:

`V=(4)/(3)\pi r^3`

The original sphere, with radius r=3, has volume:

`\begin{gathered} V=(4)/(3)\pi(3)^3 \\ =36\pi \end{gathered}`

The second sphere, with radius r=9, has volume:

`\begin{gathered} V=(4)/(3)\pi(9)^3 \\ =972\pi \end{gathered}`

To find how much the volume increased we substract the first volume to the second one:

`972\pi-36\pi=936\pi`

Therefore the v