Finding Velocity from Force, Comsol Multiphysics (transient)

[Nick Bruno]

Hi,
I am using Comsol Multiphysics to model a magnetic plug surounded by water in a tube.

The plug interacts with a magnet and a force is induced.

Since I am using the ALE moving mesh option, i have defined the boundaries of the geometry to move with the velocity of the plug.

This velocity was found by using the momentum equation ( force = dp/dt where p = mv )

m = mass; v = velocity. I separated and integrated, to find xvel = F*t/mass + c where C can be neglected.

Is there any other way to determine the velocity of the plug based off of the force produced by the magnet that DOES NOT include time (t)?

Regards,
Nick