Relative Speed Condition Applies Only to Elastic Collisions
Incorrect Thinking
Students may use relative speed of approach equals relative speed of separation for every one-dimensional collision.
Why Students Think This
The condition is compact and easy to remember, so it may be used as a shortcut without checking collision type.
Correction
Use the relative speed condition only for one-dimensional elastic collisions. For inelastic collisions, use momentum conservation and any additional information given.
Links
- Related: dynamics