If an electron, initially at rest, is accelerated through a potential difference of 180 kV, the relativistic mass of the electron is A) 12.3 × 10^-31 kg. B) 9.11 × 10^-31 kg. C) 16.2 × 10^-31 kg. D) 5.90 × 10^-31 kg. E) infinite.

Question

Quizplus · Accepted Answer

The relativistic mass of the electron is given by the equation:$$m_r = \frac{m_0}{\sqrt{1 - \frac{v^2}{c^2}}}$$where:* $$m_r$$ is the relativistic mass* $$m_0$$ is the rest mass of the electron* $$v$$ is the velocity of the electron* $$c$$ is the speed of lightIn this problem, the electron is initially at rest, so $$v = 0$$. The potential difference of 180 kV is converted to kinetic energy, which is then used to calculate the velocity of the electron. The relativistic mass of the electron is then calculated using the equation above.The correct answer is A) 12.3 × 10^-31 kg.

If an Electron, Initially at Rest, Is Accelerated Through a Potential