Answer to Question #294067 in Mechanics | Relativity for lenard

Question

The rest mass of an electron is 9.1 x

10^-31 kg. What is the relativistic mass if its velocity is 55 % of the speed

of light?

Answer 1

$m=\frac{m_0}{\sqrt{1-\frac{v^2}{c^2}}}=10.9\cdot 10^{-31}~kg.$