Conservation of Momentum
1D Conservation of Momentum
If the impulse on a system is approximately zero, which occurs if the net force is very small or the duration of the force is very small, then the change in momentum is also approximately zero. That means that if you vectorially add up all the momentum in your system initially, it will equal the net momentum of the system finally. Mathematically this can be written as $\sum{\vec{p}_i} = \sum{\vec{p}_f}$. Applying momentum conservation when applicable will allow you to determine the motion of systems before and after collisions and other interesting scenarios.
2D Conservation of Momentum
Conservation of Momentum in 2 dimensions follows the same fundamental equations and principles as in 1 dimension. The main difference is that you must use a component analysis and conserve momentum in in both x and y directions.
