Dimensional formula of Heat flux

How to get the dimensional formula of heat flux

1. Start from the definition: heat flux = power / area.
2. velocity = length / time, so velocity is [L] / [T] = [L T^-1].
3. acceleration = velocity / time, so acceleration is [L T^-1] / [T] = [L T^-2].
4. force = mass × acceleration, so force is [M] × [L T^-2] = [M L T^-2].
5. displacement = length, so displacement is [L] = [L].
6. work = force × displacement, so work is [M L T^-2] × [L] = [M L² T^-2].
7. power = work / time, so power is [M L² T^-2] / [T] = [M L² T^-3].
8. Put in the dimension of each part: [M L² T^-3] / [L²].
9. Add the powers of each base quantity: [M T^-3].

Quantities with the dimensions [M T⁻³]

• Solar constant
• Intensity of a wave
• Poynting vector

Equal dimensions do not make them the same quantity. Compare heat flux with the others in the full grid.

Three questions on heat flux

Related quantities

• Q Heat [M L² T⁻²]
• C Heat capacity [M L² T⁻² K⁻¹]
• c Specific heat capacity [L² T⁻² K⁻¹]
• C Molar heat capacity [M L² T⁻² K⁻¹ mol⁻¹]
• L Latent heat [L² T⁻²]
• K Thermal conductivity [M L T⁻³ K⁻¹]