The relativistic total energy of a particle is given by:
[tex]E^2= (pc)^2+(m_0 c^2)^2 [/tex]
where
p is the particle momentum
c is the speed of light
[tex]m_0[/tex] is the rest mass of the particle
If we re-arrange the equation, we find
[tex]p= \frac{1}{c} \sqrt{(E^2-(m_0c^2)^2} [/tex]
and by using
[tex]c=3 \cdot 10^8 m/s[/tex]
[tex]m_0 = 1.67 \cdot 10^{-27} kg[/tex] (proton mass)
we find the momentum of the proton:
[tex]p= \frac{1}{3\cdot 10^8 m/s} \sqrt{(3.0 \cdot 10^{-10}J)^2-(1.67\cdot 10^{-27}kg (3\cdot 10^8 m/s)^2)^2} =[/tex]
[tex]=8.65 \cdot 10^{-19} kg m/s[/tex]
