In two dimensions, the total vector momentum is still conserved. That means that each component of momentum remains the same before and after the encounter.
I recommend building a table to help you keep track of the momentum before and after a collision.
Okay, let's try some examples.
These examples with bricks and pucks may seem abstract. Does momentum really play a part in real life? It sure does! Consider the sport of relay speed skating.
Now, sometimes, you'll see situations in which it's not clear whether you ought to use conservation of energy, or conservation of momentum .... or maybe even BOTH. Learning which tool to use is a skill that only comes with practice and experience.
Copyright © Michael Richmond. This work is licensed under a Creative Commons License.