How to derive it
Start from a formula that defines coefficient of viscosity, then replace each quantity with its dimensions. M is mass, L is length, T is time.
- Rearrange: η = F ÷ (A × dv/dx)
- dv/dx = velocity ÷ distance = [LT⁻¹] ÷ [L] = [T⁻¹]
- η = [MLT⁻²] ÷ ([L²] × [T⁻¹])
- So [coefficient of viscosity] = [ML⁻¹T⁻¹], also written [M¹L⁻¹T⁻¹].
Dimensional formulas of other quantities
The full searchable list, with SI units, is on the dimensional formula page.
Questions students ask
What is the dimensional formula of coefficient of viscosity?
[ML⁻¹T⁻¹] (or [M¹L⁻¹T⁻¹]), from F = ηA (dv/dx). Its SI unit is Pa s = N s m⁻² (poise in CGS).
What are the dimensions of coefficient of viscosity?
M: 1, L: -1, T: -1.
What is the SI unit of coefficient of viscosity?
Pa s = N s m⁻² (poise in CGS).