I understand that force is equal to the time derivative of momentum, or d(mv)/dt. Then what happens if the velocity is constant and only the mass is changing. Does this mean there will be a force. If so, in what direction since I am assuming it is still a vector. Also, what if the mass and velocity are changing, does this make some kind of "2nd order" force?(adsbygoogle = window.adsbygoogle || []).push({});

Any help would be appreciated.

Thanks.

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# What happens to Newton's 2nd law if there is a changing mass?

**Physics Forums | Science Articles, Homework Help, Discussion**