Answer
$7.245g/cm^3$
Work Step by Step
Volume of a sphere $= \dfrac{4}{3}\pi r^3$
Circumference of a circle $= 2\pi r$
First we will find $r$ from the circumference, then find the volume of the sphere.
$32.5mm = 2 \pi r$
$r = \dfrac{32.5mm}{2\pi}$
plug our $r$ into the volume equation:
volume $= \dfrac{4}{3}\pi r^3$
volume $= \dfrac{4}{3}\pi (\dfrac{32.5mm}{2\pi})^3$
volume $= 579.69mm^3$
$579.69 mm^3*\dfrac{(1cm)^3}{(10mm)^3}$
$579.69 mm^3*\dfrac{1cm^3}{10^3 mm^3}$
$579.69 * 10^{-3}cm^3$
$0.57969 cm^3$
density $= \dfrac{4.20g}{0.57969 cm^3}$
$$7.245g/cm^3$$
