Answer
See example.
Work Step by Step
This problem is solved and explained in Example 42.8.
Set $\frac{3}{2}kT=\frac{1}{2}mv_{rms}^2$
Solve for $v_{rms}=1.17\times10^5 m/s$.
This is much smaller than the speed of an electron whose kinetic energy is the Fermi energy of copper. It just goes to confirm that temperature plays a very small role in determining the electronic properties in metals. The average energies are determined mostly by the Pauli exclusion principle.
