Since force is related to a change in momentum and not necessarily just to a change in velocity, what would be an example where only the mass of a body changes but not its velocity when subjected to a force?

Question

Since force is related to a change in momentum and not necessarily just to a change in velocity, what would be an example where only the mass of a body changes but not its velocity when subjected to a force?

In: Physics

Answer 1

If we use a rocket as an example, this situation would mean the thrust of the rocket (which is achieved by ejecting mass) equals its weight (the external force acting on the rocket), therefore there’s no acceleration (the rocket may be hovering or moving at a constant velocity). It just describes how the forces are balanced, it doesn’t mean the external force is causing the mass to change. In the absence of the external force (no gravity) the rocket can still eject mass and accelerate.