1.what happens to momentum when mass
increases or decreases?

2. what happens to momentum when
velocity increases or decreases?

3.what is the mathematical relationship
between mass/velocity and momentum?

1. Mass is directly proportional to momentum, so increasing/decreasing it will also cause the momentum to increase/decrease accordingly.

2. Velocity is also directly proportional to momentum, so the same as #1.

3. Mass and velocity are both directly proportional to momentum, so changing either (or both) will cause the momentum to change accordingly. Doubling velocity will double the momentum, halving mass will half the momentum, and so on.