Physics Ontology

One map of physics, three ways in. Drill down on any quantity to see its units, the equations it lives in, and how its values span the universe.

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e/m_p

Fundamental Constants

Proton Charge–Mass Ratio

Ratio of elementary charge to proton rest mass.

SI unit

coulomb per kilogram (C/kg)

Dimension: $[\,I T M^{-1}\,]$

Other units

coulomb per kilogram (C/kg)

Defined value

Fixed constant from the A-level data sheets.

9.58 × 10⁷ C/kg

AQA data sheet value