For example, if the momentum p of an electron is 1 GeV/ c, then the conversion to MKS system of units can be achieved by: p = 1 GeV / c = ( 1 × × 10 9 ) × × ( 1.602 176 634 × × 10 − − 19 C ) × × ( 1 V ) 2.99 792 458 × × 10 8 m / s = 5.344 286 × × 10 − − 19 kg ⋅ ⋅ m / s .