convservation of momentum if one object rolls.

[powerball]

If 2 molecules collide, m1u1+m2u2 = m1v1+m2v2. However lets say the object hit rolls. How would that factor be dealt with in terms of momentum

[HallsofIvy]

By including the angular momentum: moment of inertia times angular velocity.

[powerball]

can you combine an equation with linear and angular momentum or do you have to do it independently? e.g in the case of a flow of water causing a ball to roll