Question

A total charge of 6.3×10−8 C is distributed uniformly throughout a 2.7-cm radius sphere. What is the volume charge density?

Answer 1

$q=6.3\times10^{-8} C$

$r=2.7$ cm $=2.7\times10^{-2} m$

let's first find volume $V={\frac 4 3}\pi r^3=8.24\times10^{-5} m^3$

Then volume charge density $\rho=q/V=7.65\times10^{-4} {\frac C {m^3}}$