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Modern Physics
Modern Physics

Energy-Momentum Relation

E2=(pc)2+(mc2)2E^2 = (pc)^2 + (mc^2)^2

Relates energy, momentum, and mass. For massless particles (photons): E = pc.

Variables

E
Total energy
J
p
Momentum
kg·m/s
m
Rest mass
kg
c
Speed of light
m/s

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Common questions

What is the Energy-Momentum Relation formula?

Energy-Momentum Relation is written E² = (pc)² + (mc²)². Relates energy, momentum, and mass. For massless particles (photons): E = pc. It belongs to Modern Physics, under Special Relativity.

What are the units in E² = (pc)² + (mc²)²?

In SI units, E is total energy, measured in J; p is momentum, measured in kg·m/s; m is rest mass, measured in kg; c is speed of light, measured in m/s.