Aside: Ordinary vs. partial derivatives

Fluid mechanics usually involves partial derivatives rather than ordinary derivatives. This is because we model fluids as continuous materials in three-dimensional space. This clip also mentions the Knudsen number and the point at which the continuum model will break down.

[@awaismirza7908]

Misleading title: it's about the continuum model altogether, not a single mention of derivatives.

[@mohammedalbahrani5109]

A brief explanation Thank you sir

[@Wonderlinger]

The correct pronounciation of Knudsen is Knussen - the K is NOT silent.