Types of Waves Longitudinal The displacement of particles is parallel to the direction of the wave. Sound waves that travel through the air are longitudinal Imagine the coils in a slinky as they spring from one end to the other
Types of Waves Transverse The displacement of particles is perpendicular to the direction of the wave. Ripples on a pond are longitudinal waves. Imagine the motion of a sting on an instrument as it is plucked.