Question

What is the radius of the sphere? What is the volume of the spherical stone?

Answer 1

$\begin{gathered} R=4ft \\ V=\frac{256}{3}\pi ft³ \end{gathered}$

1) Since the sphere has a diameter of approximately 8 feet, then we can tell that:

$D=2R,\Rightarrow2R=8\Rightarrow\frac{2R}{2}=\frac{8}{2}\Rightarrow R=4ft$

Note that the radius is always half the diameter.

2) Now, let's find the volume of this sphere. Note that there is a formula for the volume of a sphere. This is:

$\begin{gathered} V=\frac{4}{3}\cdot\pi\cdot R^3 \\ V=\frac{4}{3}\pi\cdot4^3 \\ V=\frac{4}{3}\pi *64 \\ V=\frac{256}{3}\pi ft³ \end{gathered}$