Since momentum itself is a reaction of force on the molecules that put it into a state of movement, I would think it would either continue once it rematerialized, or be moving as it is reintegrated.
It would really depend on the mechanics of the device.
Say the device temporarily freezes time somehow around the object so that all molecular activity stops till the process is complete.
Then the stasis field if you will is released.
The object should continue again since the molecules were not given a chance to release the energy from movement.
If the devise were to work slower than the movement of an object.
As in they have a sign that says "Hold your breath and remain perfectly still till we tell you to move."
If you were to throw a ball, and activate the process, the ball may come out at the other end in a dust form since the molecules did not reassemble properly.
Or the ball may elongate into a stretched oval of sorts.
You would think the process would take either the stasis field concept, or use an event horizon.
As in on one side of a line your here, on the other you are there, where ever there may be.... instantly as you cross the line.
In the earlier Star Trek series, the effect usually had the stasis look.
You froze, sparkled, stopped sparkleing, then moved.. ahhh it's done I can breathe again.
This was because of the lack of special effects technology.
In later series like Star Trek the next generation, you would see them standing still on the planet while dematerializing.
Then they would be in the middle of a conversation while rematerializing, like there was a tunnel effect with a delay that you were conscience of.
Forgive me, I grew up on Star Trek, and live about a half hour from the future birth place of James T Kirk.
I don't consider myself a Trekker as much as a child of science fiction.
{and yes it's Trekker, not Trekky, the geeks find insult in being called a Trekky}
Teleportation is an itreguing concept, but highly improbable.