Waves

Longitudinal Wave

In longitudinal waves the displacement of the medium is parallel to the propagation of the wave. A wave in a "slinky" is a good visualization. Sound waves in air are longitudinal waves. (particle moves left to right)

Speed

the distance traveled by a given point on the wave (such as a crest) in a given interval of time. In equation form = distance/time

Music

A musical sound is called a tone, and is produced by air vibrating a certain number of times per second. These vibrations are called waves. These sound waves must be contained in some way so that the performer can control the loudness, quality of the tone, and how long it plays. Most musical instruments have a reed, a string, or some other device that creates sound waves when moved. Sounds are different because of harmonics, which are higher and quieter sounds mixed in. They are not heard separately, but add to the tone of the sound, making an oboe sound different from a trumpet or drum.

Wave

A wave is a disturbance that moves along a medium from one end to the other. If one watches an ocean wave moving along the medium (the ocean water), one can observe that the crest of the wave is moving from one location to another over a given interval of time.

Fiber Optics

An optical fiber (or optical fibre) is a flexible, transparent fiber made of a pure glass (silica) not much thicker than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. Optical fibers are widely used in fiber-optic communications, which permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communication. Fibers are used instead of metal wires because signals travel along them with less loss and are also immune to electromagnetic interference. Fibers are also used for illumination, and are wrapped in bundles so that they may be used to carry images, thus allowing viewing in confined spaces.

Doppler Effect

As waves move toward something, the frequency between it and something in front of it are short and therefore higher. And then as it moves away the frequency is less and lower.

Refraction

Change in direction due to a change in speed

Transverse Wave

For transverse waves the displacement of the medium is perpendicular to the direction of propagation of the wave. A ripple on a pond and a wave on a string are easily visualized transverse waves. (particle moves up and down)

Frequency

Frequency refers to how many waves are made per time interval. This is usually described as how many waves are made per second, or as cycles per second.

Scattering

Scattering theory is a framework for studying and understanding the scattering of waves and particles. Prosaically, wave scattering corresponds to the collision and scattering of a wave with some material object, for instance sunlight scattered by rain drops to form a rainbow.

Characteristics of Sound

Sound is a longitudinal, mechanical wave. Sound can travel through any medium, but it cannot travel through a vacuum. There is no sound in outer space. Sound is a variation in pressure. A region of increased pressure on a sound wave is called a compression (or condensation). A region of decreased pressure on a sound wave is called a rarefaction (or dilation). The speed of sound depends upon the type of medium and its state. It is generally affected by two things: elasticity and inertia. The frequency of a sound wave is called it pitch. Briefly, the intensity of a sound wave is a combination of its rate and density of energy transfer. It is an objective quantity associated with a wave. Loudness is a perceptual response to the physical property of intensity. It is a subjective quality associated with a wave and is a bit complex. As a general rule the larger the amplitude, the greater the intensity, the louder the sound. Sound waves with large amplitudes are said to be "loud". Sound waves with small amplitudes are said to be "quiet" or "soft".

Polarization

The phenomenon in which waves of light or other radiation are restricted in direction of vibration. Polarized light waves are light waves in which the vibrations occur in a single plane. It can occur through transmission, reflection, refraction, or scattering.

Superposition

The principle of superposition may be applied to waves whenever two (or more) waves travelling through the same medium at the same time. The waves pass through each other without being disturbed. The net displacement of the medium at any point in space or time, is simply the sum of the individual wave displacements. (the One on the left will end up on the right, traveling in the same direction and so on)fl

Dispersion

The separation of ocean waves by wavelength as they travel away from their point of origin. Longer waves travel faster.* Waves come from storms, there are a bunch of waves near a storm and they have different wavelengths. The longer the wavelength the faster the period and the faster it travelers. These move away faster then others and reach the shore later... Waves separate according to their speed basically. Separation by speed forms groups of waves with similar wavelengths called ocean swells.

Wavelength

The wavelength of a wave is the distance between any two adjacent corresponding locations on the wave train.

Interference

Two or more waves traveling in the same medium travel independently and can pass through each other. In regions where they overlap we only observe a single disturbance. We observe interference. When two or more waves interfere, the resulting displacement is equal to the vector sum of the individual displacements. If two waves with equal amplitudes overlap in phase, i.e. if crest meets crest and trough meets trough, then we observe a resultant wave with twice the amplitude.

Transmission

When a wave goes from one material to another it changes. From fast to slow the wavelength gets smaller because as it enters the new material it slows down front to back and bunches. If it is from slow material to fast it is the opposite.

Reflection

When waves get into a new material, some will be reflected. It is reflected backwards but up side down and the amplitude is smaller. Wavelength is the same thought. The Reflected amount and Transmitted amount add up to the original wave amount. If Slow material to Fast material then the reflection is same side up because doesn't hit anything.

Addition

adding colors to make white

Amplitude

amplitude is the maximum positive displacement from the undisturbed position of the medium to the top of a crest. (x-axis to top crest)

Convex Lens

cause parallel light rays to converge (go toward the middle)

Concave Lens

cause parallel light rays to diverge (go out)

Subtraction

subtracting colors to make black

Absorption

the transfer of the energy of a wave to matter as the wave passes through it.

Diffraction

when light passes sharp edges or goes through narrow slits the rays are deflected(change direction) and produce fringes of light and dark bands