Mechanical Waves

Transverse Waves

In a transverse wave the particle displacement is perpendicular to the direction of wave propagation. The animation below shows a one-dimensional transverse plane wave propagating from left to right. The particles do not move along with the wave; they simply oscillate up and down about their individual equilibrium positions as the wave passes by. Pick a single particle and watch its motion.

With transverse wave, you can see the motion medium that makes up the wave doesn't move in the direction of the wave.

Graphic provided by GCSE Science

Longitudinal Wave

In a longitudinal wave the particle displacement is parallel to the direction of wave propagation. The animation below shows a one-dimensional longitudinal plane wave propagating down a tube. The particles do not move down the tube with the wave; they simply oscillate back and forth about their individual equilibrium positions. Pick a single particle and watch its motion. The wave is seen as the motion of the compressed region (ie, it is a pressure wave), which moves from left to right.

With longitudinal waves the medium is constants moving back and for in the same direction of the wave.  What this means is a particle in the wave is constantly moving back and forth, without really knowing if its moving in the direction or against the motion of the wave.

With transverse wave the particles never change in it's position in the direction wave,  with the longitudinal the net motion of the particle doesn't change.