What type of wave is created when the motion of particles of a medium is transverse to the direction of propagation?

When considering the motion of particles in a medium in relation to wave propagation, a shear wave, also known as a transverse wave, is characterized by the particle motion being perpendicular (or transverse) to the direction the wave travels. This is in direct contrast to longitudinal waves, where the particles of the medium move parallel to the direction of wave travel.

In shear waves, the displacement of the medium's particles creates a disturbance that moves through the material. This behavior is critical in various applications, particularly in ultrasonic testing, where shear waves are utilized to inspect materials for flaws. Shear waves cannot travel through fluids since fluids do not support shear stress.

In this context, the term "acoustic wave" generally refers to sound waves regardless of type, and "mechanical wave" encompasses both longitudinal and shear waves, making them broader categories that include various wave types. However, for the specific definition of particle motion being transverse to wave direction, shear wave is the precise term that applies.