Relativistic Momentum and Energy

Momentum and energy is always conserved.

p= γm_o v, where p is the relativistic momentum, v is the speed of the particle and m_o is its mass as measured by an observer at rest with respect to the particle.

Rest energy, E_o = m_oc²

Total energy, E = γm_oc²

Kinetic energy, KE = γm_oc² – m_oc²

∆E = ∆mc²

E = γE_o

K.E = (γ – 1)E_o

E² = p²c² + (m_oc²)²


For particles that have zero mass, such as protons, m_o = 0, E = pc

1 eV = 1.602 x 10^-19 J

1 eV : energy required to accelerate an e- through a potential difference of 1 volt.

1 u = 1.66 x 10^-27 J

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