Is Momentum Conserved?

Motion in Osmos is based on the concept of the conservation of momentum – expelling a small mote in one direction causes the player to move in the opposite direction… but is momentum actually conserved in the game?

This is a big question that can be explored in a variety of ways — let’s begin by just focusing on the propulsion of the player.
Is momentum conserved when the player expels a small mote?

To answer this question, you will probably need to answer a few others:

• How does the mass of the player compare to the mass of the expelled mote?

• How can we determine the velocity of the motes? (Should we use video analysis?)

• Do we need to know the absolute velocity or will relative velocity suffice?

Upload your solution as a comment.
Bonus points to the simplest and most elegant solution method.