In this post, we will list down the differences among the 3 primary types of collisions, elastic, inelastic & perfectly inelastic collisions. Among these types of collisions, elastic and perfectly inelastic collisions are limiting cases; most collisions actually fall into a category between these two extremes. In this third category of collisions, called inelastic collisions, the colliding objects bounce and move separately after the collision, but the total kinetic energy decreases in the collision. Here is a detailed post on the fundamentals of collisions that you can go through.
Differences among elastic, inelastic & perfectly inelastic collisions
Let’s present these differences in tabular form.
|Type of collision||What happens||Conserved Quantity|
|perfectly inelastic||The two objects stick together after the collision so that their final velocities are the same.||momentum|
|elastic||The two objects bounce after the collision so that they move separately.||momentum & Kinetic energy|
|inelastic||The two objects deform during the collision so that the total kinetic energy decreases, but the objects move separately after the collision.||momentum|