Are there any cases in newtonian physics where it is valid to apply Newton's second law in the form Ʃ(adsbygoogle = window.adsbygoogle || []).push({}); = m dF/dt +vdm/dt, in which dm/dt is non-zero?v

It is my belief that there are no such cases. For example, if one applies momentum conservation to a rocket in a field-free region, we obtain an equation which is consistent with Ʃ= m dF/dt (that is Ʃv= mF), but not with Ʃa= m dF/dt +vdm/dt.v

Despite my scepicism, the original question is a genuine one.

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# Newton's second law if mass changes

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