For the manga character, see Berserk (manga).

femto- is an SI prefix (symbol f) in the SI system of units denoting a factor of 10⁻¹⁵ or 0.000 000 000 000 001. Adopted in 1964 by the 12th Conférence Générale des Poids et Mesures, it comes from the Danish or Norwegian femten, meaning fifteen.

Examples:

• One femtosecond = 10⁻¹⁵ s
• One femtojoule = 10⁻¹⁵ J

Note that the femtometre (10⁻¹⁵ of a metre) shares the same unit symbol (fm) with the older non-SI unit fermi, to which it is equivalent. The fermi, in honour of Enrico Fermi is often encountered in nuclear physics that is characteristic of this scale.

External links

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• Bureau International des Poids et Mesures (BIPM)

SI prefixes

Femto | Femto | Femto | Femto | Femto | 펨토 | Femto | Femto | フェムト | Femto | Femto | Femto | Femto | Фемто | Femto | Femto | Femtô