4.5: More Collisions
Elastic Collisions
In the previous section, we focused on inelastic collisions. Here we will look at elastic collisions, where the kinetic energy of the system remains unchanged, meaning none of the rest frame kinetic energy is converted into thermal energy. This kind of collision is standard between particles, but between macroscopic objects, this is really only an approximation. When we are told that a given collision is elastic (or at least can be approximated as such), then that gives us an additional condition that we can use to solve the problem. We'll go through a few examples of elastic collisions in one dimension below. In each case, the diagram will show the experimental result, which we will then show mathematically using the combination of momentum and kinetic energy conservation.