## College Physics (7th Edition)

The expression for sphere volume is incorrect in Exercise 12. Volume of a sphere in terms of diameter $d$ is $V=\pi d^3/6$.
The correct equation for sphere volume is given as, $V=\frac{4}{3}\pi r^3$. diameter is expressed as $d=2r$. Substituting, for $r$ in equation for volume - $V=\frac{4}{3}\pi (\frac{d}{2})^3=\frac{4}{3}\pi \frac{d^3}{8} = \frac{1}{6}\pi d^3$. The expression for sphere volume in Exercise 12 is incorrect.