Answer
$2.42\times 10^{-3}$
Work Step by Step
We can find the ratio $\frac{v}{c}$ as follows:
$\frac{v}{c}=\frac{2\pi Ke^2}{nhc}$
We plug in the known values to obtain:
$\frac{v}{c}=\frac{2\pi(8.99\times 10^9)(1.60\times 10^{-19})^2}{2(3.00\times 10^8)(6.63\times 10^{-34})}$
$\frac{v}{c}=2.42\times 10^{-3}$
