I'm trying to understand why the del operator is working a certain way.(adsbygoogle = window.adsbygoogle || []).push({});

So in my literature there is a term:

[itex]\nabla \cdot \rho_a \mathbf{v}[/itex]

but then after saying that

[itex]\rho_a=w_a\rho[/itex]

the term can somehow become

[itex]\rho (\mathbf{v}\cdot \nabla w_a)[/itex]

I do not understand how nabla and the velocity, v, get flipped.. Is there some assumption that needs to be made for this to be true?

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# Del operator and divergence

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