- #1

Slimy0233

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- TL;DR Summary
- Need to know the kinetic energy of an electron moving with velocity v to find the total energy of an electron moving with velocity v

**note:**

m = relativistic mass

##m_o## = rest mass

v = velocity of the objectQuestion 1: If a particle is moving at relativistic speeds what would it's kinetic energy be?

m = relativistic mass

##m_o## = rest mass

v = velocity of the object

I think it's ##K.E. = \frac{1}{2} m_o v^2## and my friend thinks it's ##K.E. = \frac{1}{2} \frac{m_o v^2}{\sqrt{1-\frac{v^2}{c^2}}}##

Who is right? Is it relativistic mass or rest mass?

Also, if an electron is moving with a velocity v, would it's total energy be

A fellow student said it's 1. $$E_{total} = mc^2 + \frac{1}{2} \frac{m_o v^2}{\sqrt{1-\frac{v^2}{c^2}}}$$

Now, I think it's either

2. ##E_{total} = m_o c^2 + \frac{1}{2} m_o v^2## or 3. ##E_{total} = mc^2##

Who is right?