Dr. Makin Advanced 7 th Science Clarence Middle School

 Are created when a source of energy causes a vibration to move through a medium.

 Is a wave that causes the medium to vibrate perpendicular to the direction of the wave.

 Is a wave in which the vibration of the medium (movement of the particles) is parallel to the wave direction.

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 Are waves that travel along a surface separating a media. It contains both transverse and longitudinal waves.

 Periodic frequency is any motion that repeats at regular intervals and any periodic motion has frequency, which is the # of complete cycles in a given time period.  Frequency = cycles /s or hertz (Hz) or 1/s

 Wavelength is the distance between a point on one wave to the same point on the next wave in a cycle recorded in meters(m).

 Wave speed = Wavelength * Frequency  Or v = λ * f v = speed(m/s) λ =wavelength(m) f = frequency(Hz or 1/s)

 Amplitude is the maximum displacement of a wave from its rest position. It can be measured from the trough or the crest to rest.  rest

RReflection is when a wave bounces off a surface it cannot pass through. It does not change the speed or frequency of a wave but the wave can be flipped upside down.

RRefraction is the bending of a wave as it enters a medium at an angle. It occurs because one side of the wave is moving more slowly than the other.

DDiffraction is the bending of a wave as it moves around an obstacle. The larger the wavelength in comparison to the obstacle the more it diffracts.

IInterference occurs when two or more waves overlap and combine together. They can be constructive or destructive.

AAre transverse waves consisting of electric fields and changing magnetic fields. They are produced when an electric charge vibrates or accelerates. They can travel through a vacuum or a medium.

AAlbert Michelson measured the speed of light more accurately then his predecessors. He used a series of mirrors to do it.

A X10 8 m/s B. Or 6.7x10 8 mph WWhen calculating wave frequency of EMS we use A for speed

SSometimes light behaves as both. TThomas Young showed that light behaves as a wave.

HHeinrich Hertz found that shining a light on metal emitted electrons. It was later determined by Einstein that light is composed of Photons and that the higher the energy of the wave the greater its ability to emit electrons from a medium like metal.

DDecreases as photons travel farther from their source.