# Divergence of mass current density

Hi,

i thought a while about the meaning of the following expression

$$\delta t \, \cdot \, \mathrm{div} \, \vec j_m(\vec r,t) \qquad \mathrm{with} \qquad \vec j_m(\vec r,t) = \rho_m(\vec r,t) \cdot \vec v(\vec r, t)$$​

Does it indicates the mass, which is produced / annihilated in the Volume $$\mathrm{d}V$$ located around the position vector $$\vec r$$ in the short time interval $$\delta t$$!?

I'm pretty sure that it was something like this but not entirely.

So, thanks for your effort and with best regards...

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