​Types of Waves

• Waves may be categorized based on whether or not they need a medium.

• ​There are two types of waves:

  • 1.) Mechanical waves: require a medium (matter) to travel.

    2.) Electromagnetic (EM) waves: do NOT require a medium to travel.

​Mechanical waves

• ​These require a medium for the vibrations to travel and so cannot travel through space (vacuum)

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• ​May either move as transverse or longitudinal waves.

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• ​Ex. sound, water wave, slinky,

​​Mechanical waves

• ​The speed at which they travel depends on either the type of wave or the medium they are in.

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• ​They travel fastest in more dense medium. Therefore, they move fastest in solids and slowest in gases.

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• ​Generally, these have longer wavelengths than electromagnetic waves.

​Electromagnetic Wave

• ​A waves that does NOT require a medium (matter to travel), has an electric field component and a magnetic field component.

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• ​These two fields move perpendicular to the propagation of the wave and so they are all transverse waves

​Electromagnetic waves

• ​All electromagnetic waves travels at the speed of light 3.0 x 10⁸ m/s in a VACUUM. However, they travels at different speeds when traveling through matter.

• They travel fastest in less dense medium, so fastest in gases and slowest in solids.

• Ex: Radio waves, Microwaves, Infrared, Visible Light, Ultraviolet, X-rays, and Gamma Ray.

​Electromagnetic Spectrum

• ​Shows a visual display of various electromagnetic waves to compare their relative wavelengths and frequencies.