
$\mathrm{F}_{\mathrm{m}}=1.6 \times 10^{-19} \times 10^{5}\left(\frac{2 \times 10^{-7} \times 10}{4 \times 10^{-2}}\right)$
$F_{\mathrm{m}}=0.8 \times 10^{-18}\, \mathrm{N}$


(mass of proton $=1.67 \times 10^{-27} \,kg ,$ charge of the proton $\left.=1.6 \times 10^{-19}\, C \right)$
