Transverse and longitudinal waves differ in one thing: whether the medium wobbles across the travel or along it. Drag the sliders below to set the frequency, wavelength and amplitude, and compare crests and troughs against compressions and rarefactions.
The only thing separating a transverse wave from a longitudinal one is a single question about the medium: does it wobble across the direction of travel, or along it? In a transverse wave the particles bob perpendicular to where the wave is heading, tracing crests and troughs as it moves sideways. Waves on a string, and light and every electromagnetic wave, belong here. In a longitudinal wave the particles shuffle back and forth parallel to the travel, bunching into compressions and spreading into rarefactions. Sound in air and a pushed slinky are the classic examples.
Watch the two animations side by side and don't be fooled by the drawing. A longitudinal wave is often plotted as a curvy, transverse-looking graph of density against position, but the particles themselves never leave their neighbourhood. Both wave types obey the same rule: v = f·λ. Because this sim lets you set the frequency and wavelength independently, turning up Frequency or stretching the Wavelength raises the computed speed readout — in a real fixed medium the medium sets the speed and the two trade off instead. The Amplitude slider only changes the energy carried, the loudness or the height, never the speed.
In either case the wave hauls energy forward while each particle merely oscillates about a fixed point; the medium itself stays put. To pin down the frequency-wavelength product, open the wave speed calculator, revisit the wave speed lab, or browse the full set of interactive physics simulations.
In a transverse wave the particles vibrate perpendicular to the direction the wave travels, making crests and troughs. In a longitudinal wave the particles vibrate parallel to the travel, making compressions and rarefactions.
Transverse waves include waves on a string and all electromagnetic waves, such as light. Longitudinal waves include sound in air and a compression pulse sent along a slinky.
Yes. Wave speed equals frequency times wavelength, v = f·λ, for both transverse and longitudinal waves. In a fixed real medium the speed is set by the medium, so frequency and wavelength trade off inversely.
No. A wave transports energy, not matter. Each particle of the medium oscillates about a fixed point while the energy moves forward; the medium itself stays put.