The equation E=pc is valid

Options

A. both
B. neither
C. photon only
D. electron only

Answer

C

Explanation

Energy is given by
`(m_0c^2)/(sqrt(1-((v^2)/(c^2))))`
or `E^2=(m_0^2c^2)/(c^2-v^2)`
Momentum p is given by `p=(m_0v)/(sqrt(1(v^2/c^2)))`
or `p^2c^2=(m_0^2c^4v^2)/(c^2-v^2)`
`E^2-p^2c^2=m_0^2c^4` or `E^2=p^2c^2+m_0^2c^4`
For photon, rest mass
`m_0=0`, so `E=pc` For electron, `m_0ne0`, so `Enepc`