Sections Key Equations Key Equations speed of light v=λf v=λf constant value for the speed of light c= 3.00 × 10 8 m/s c= 3.00 × 10 8 m/s elapsed time Δt=γΔ t 0 Δt=γΔ t 0 relativistic factor γ= 1 1− u 2 c 2 γ= 1 1− u 2 c 2 length contraction L= L 0 γ L= L 0 γ relativistic momentum p=γmu p=γmu relativistic energy E=γm c 2 E=γm c 2 rest energy E 0 =m c 2 E 0 =m c 2 Print Share Key Equations Copy and paste the link code above.