Question

How does friction affect conservation of momentum?

Answer 1

It is complicated, please see below.

Explanation:

Friction causes a continuous loss of energy in moving objects as work is done on friction. That loss of energy is shown as a gradual decrease in velocity.

If your question concerns conservation of momentum before and after some event (like a collision), it is necessary to compare momentum immediately before the event and immediately after the event. With that condition, the answer to your question is no.

Newton's 1st Law discusses momentum. Typically he is quoted something like this: "Unless acted on by an outside force, a body in motion tends to stay in motion in a straight line at the same velocity." The first 7 words rule out friction.

I hope this helps,
Steve