Wave Types in a Spring
A single slinky can carry both kinds of wave depending on how you shake it. This simulation runs transverse and longitudinal waves along the same spring so the difference in particle motion is directly comparable.
How to use this simulation
- Switch between transverse and longitudinal excitation
- Change the frequency and amplitude
- Track a marked coil through its motion
What to look for
- Transverse particles move at right angles to the wave direction
- Longitudinal particles move along it, forming compressions
- In both cases the marked coil returns to its starting position each cycle
The physics behind it
In a transverse wave the particles oscillate perpendicular to the direction of travel; in a longitudinal wave they oscillate parallel to it. Both transfer energy without net movement of matter, and both obey v = fλ. Only transverse waves can be polarised, because only they have a meaningful oscillation direction to restrict.