1Which of these has the same dimensions as mass?
Mass and atomic mass unit both have the dimensions [M].
SI base quantitiesClass 11, Units and Measurements
Dimensional formula of Mass
[M]
The SI base quantity for the amount of matter. Mass has the same dimension in every formula, weight does not.
How to get the dimensional formula of mass
- Mass is one of the seven SI base quantities, so its dimension is written directly: [M].
Quantities with the dimensions [M]
Equal dimensions do not make them the same quantity. Compare mass with the others in the full grid.
Three questions on mass
2What is the SI unit of mass?
The SI unit of mass is the kilogram (kg).
3Which one has different dimensions from the others?
Amount of substance is [mol]. The other three are all [M].
An equation that uses mass
Equation checker
Matching dimensions are necessary, not sufficient. A check cannot see pure numbers such as 1/2 or 2π, so a consistent equation can still be wrong.
Read as
E = m c2E[M L2 T-2]=mc2[M L2 T-2]Dimensionally consistentEvery term is [M L2 T-2]
Mass: quick answers
What is the dimensional formula of mass?
The dimensional formula of mass is [M]. It is one of the seven SI base quantities.
What is the SI unit of mass?
The SI unit of mass is the kilogram (kg).
Which quantities have the same dimensions as mass?
Mass shares [M] with electron mass, atomic mass unit. Equal dimensions do not make them the same quantity.