$\left(\frac{1}{4 \pi \epsilon_0}=9 \times 10^9 \mathrm{SI}\right.$ એકમ $\alpha$ કણનું દળ $=$ $\left.6.72 \times 10^{-27} \mathrm{~kg}\right)$
\(=\sqrt{\frac{4 \times 9 \times 10^9 \times 80}{6.72 \times 10^{-27} \times 4.5 \times 10^{-14}}} \times 1.6 \times 10^{-19}\)
\(=9.759 \times 10^{25} \times 1.6 \times 10^{-19}\)
\(=156 \times 10^5 \mathrm{~m} / \mathrm{s}\)