Final answer:
In studies of waves, 'medium' refers to the matter which facilitates the propagation of waves such as sound and seismic waves. The speed of sound is influenced by the properties of the medium, and in a sound wave, the density of the medium changes with each cycle. Mechanical waves need a medium to travel, and transverse waves move particles perpendicular to the wave direction.
Step-by-step explanation:
In the context of studying waves, the definition of a medium that's most likely to be used is 'the matter in which a physical phenomenon takes place.' This matter can be air, water, or any substance through which waves such as sound waves or seismic waves can travel. The medium is crucial because it helps to transfer energy and momentum from one location to another, without transferring mass. When it comes to sound waves, the medium could be air, water, or any solid through which the waves can propagate.
The speed of sound depends on the properties of the medium, such as its density and elasticity, not on the wavelength or frequency of the wave itself. Also, in a sound wave, the density of the medium varies with each cycle. It's important to understand that mechanical waves require a medium to travel, unlike electromagnetic waves, which can travel through a vacuum.
Lastly, when the particles of a medium move perpendicular to the direction of the wave motion, the wave is called a transverse wave. For example, a guitarist plucking a string creates standing waves, which are transverse waves, in the guitar string itself.