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WAVES

WAVES

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WAVES. What is wave?. A wave is a disturbance that moves from one place to another through a medium. CHARACTERISTICS OF WAVES. - PowerPoint PPT Presentation

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WAVES

WAVESWhat is wave?A wave is a disturbance that moves from one place to another through a medium.CHARACTERISTICS OF WAVESWaves are also examples of periodic motion, one that repeats itself over and over again. Periodic motion can be shown as a sine curve, as can simple moving waves.

A wave can be described by how big it is, its amplitude. It is the maximum displacement the wave causes.The amplitude is an indication of the energy contained in the wave. The larger the amplitude, the more energy in the wave. The intensity of the wave is proportional to the waves amplitude squared. It tells you the amount of wave energy that crosses a unit area per second. The intensity of a wave (and its energy) spreads out over a large area.Wavelength describes the distance from peak to peak of the wave or trough to trough of the wave.The peak of the wave is the highest point and the trough is the lowest point. In general, the wavelength is the distance between any chosen point in the wave and the next time that same point occurs.Period & FrequencyPeriod in a wave gives you the time it takes for the wave to move through one wavelength, or one cycle.

Frequency in a wave gives you number of wavelengths passing through a point, or the number of cycles per unit time. Instead of the waves period, you can talk about the waves frequency, which tells you the number of cycles of the wave per second at a point. Since frequency, is just the inverse of the period

Frequency = 1/periodYou only need to know one period or frequency- to be able to figure out the value of the other. The frequency unit of cycles per second has another name: HertzSPEEDIn a wave tells us how fast It travels in the medium.

Speed depends on the medium in which the wave is traveling. Sound travels slower in air than in water. Sounds travels slower in water than in wood.Kinds of WavesTransverse Waves- where the medium moves perpendicular to the direction in which the wave travels.Longitudinal Waves- that travel in the same direction that the medium moves.Wave ChangesUsually when there are no obstacles, there is no change in the waves wavelength, speed, direction, and so forth. If a wave suddenly encounters obstacles, such as a wall, another medium or even another wave, then there is a possibility that the waveform will change.Reflection- the turning back of a wave or at least a portion of it when it encounters an obstacle.Refraction- the change in direction of a wave as it crosses a boundary or another medium.Interference- change of the wave as it coincides with another wave.Two types of Interference

1. Constructive interference- if the change result in a wave that is bigger than the original.

2. Destructive interference- if the change result in a wave that is smaller than the original.Diffraction- change of the wave caused by slits or gaps a factor smaller than its wavelength.