What comes to mind when someone says the word wave? Maybe you picture yourself waving your hand to say hello, or a wave on the ocean. In physics, a wave can be defined as a a repeating and periodic disturbance that travels through a medium and transfers energy from one point to another. This disturbance, or variation, can move up, down, forward or back, just think of the waves in the ocean. The medium is the substance or material that carries the wave, for instance, with ocean waves the medium would be the water itself. Wave motion transfers energy from one point to another, often without permanently moving the particles of the medium. Waves are made up of oscillations (movements back and forth at a regular speed) or vibrations. All waves have an equilibrium position, which is when all the acting forces are canceled or balanced, just picture the surface of the water completely flat and smooth.
The crest of a wave is the point on the medium that exhibits the maximum amount of positive or upward displacement from the rest position, they are the uppermost points of the wave. The trough of a wave is the point on the wave that exhibits the maximum amount of negative or downward displacement from the rest position, it is the lowest position of the wave.
There are many different kinds of waves. Two kinds of waves are transverse waves and longitudinal waves. A transverse wave is a wave that has its disturbance perpendicular to its direction of propagation; the particles do not move along with the wave; they simply vibrate up and down about their individual equilibrium positions as the wave passes by. A good way to visualize a transverse wave is a string or a rope being moved up and down. The rope is moving, but it is not going anywhere, and it moves up and down.
A longitudinal wave has its disturbance along the direction of propagation. The particles do not move up or down with the wave; they simply oscillate back and forth about their individual equilibrium positions. The wave itself is the motion of the compressed region. Think of a longitudinal wave as a slinky. The slinky also moves without actually going anywhere, but it goes back and forth rather than up and down.
A compression is the point on the medium through which a longitudinal wave is traveling that has the maximum density. Think of the tight areas of the slinky as the compressions that move through the wave. A rarefaction is a point on a medium through which a longitudinal wave is traveling that has the minimum density, those would be the stretched out parts of the slinky.
While a transverse wave has an alternating pattern of crests and troughs (tops and bottoms) and it vibrates up and down, a longitudinal wave has an alternating pattern of compressions and rarefactions (dense and less dense areas) and vibrates back and forth.
There are several properties that can be found in a wave. One of them is amplitude, which is the maximum displacement of wave in relationship to the...