Mechanical waves, such as sound waves, would be created if an energy source caused a medium to vibrate.
Energy vibrating a medium produces energy waves that are mechanical waves, which means that they require a medium through which to travel.
A medium refers to a substance through which energy can be transferred from one location to another, from one particle to another. A medium can be either a solid, liquid, or a gas. As an illustration, the mechanical waves of sound travel the fastest through solid because the particles are so close to one another.
Mechanical waves can be:
- traverse, with up-and-down crests and troughs
- longitudinal, with compressions and rarefactions
- surface, with combined up-and-down and back-and-forth motion (combining traverse and longitudinal characteristics)
To continue the illustration, sound waves are classified as longitudinal waves. Longitudinal waves, with compressions and rarefactions, move in a back and forth motion.