2. Waves A wave is a back and forth motion that carries energy through matter or through space.
3. Characteristics of a Wave The highest points on a wave are called crests. The lowest points are called troughs.
4. Characteristics of a Wave Wavelength is the distance between one crest or trough to the next.
5. Characteristics of a Wave Amplitude is a measure of the wave’s height from the resting position. Amplitude is equal to one-half of the vertical distance between a crest and trough. Waves with larger amplitudes carry more energy.
6. Characteristics of a Wave Frequency of a wave is a count of either the number of crests or the number of troughs that pass a point in a given amount of time. The higher the frequency, the more energy the wave carries. Frequency is measured in units of hertz (Hz). One Hz = one wave per second.
7. Two types of waves Waves are generally one of two basic types: Mechanical Electromagnetic
8. Mechanical Wave Mechanical waves travel through matter by creating vibrations in a medium. The medium can be any type of matter: Solids Liquids Gases Examples of Mechanical waves: Sound Seismic waves Water waves
9. Electromagnetic Waves Electromagnetic waves are not caused by a disturbance of particles in a medium. It is produced by an interaction between an electric and magnetic field. Examples: X-rays Microwaves Radio waves Visible light
10. Electromagnetic Spectrum An electromagnetic spectrum is a range of radiant energy arranged in order of wavelength and frequency.
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12. Radio Waves Have some of the longest radio wavelengths of all electromagnetic waves. Low energy waves. Radio and Television stations use radio waves.
13. Microwaves Short wavelengths High frequency Carry more energy than radio waves Uses: Cell Phones Radars Microwave ovens
14. X-Rays and Gamma Rays X-Rays High energy Short wavelengths Greater penetrating power Gamma Rays More energy than X-Rays Produced by some nuclear reactions
15. Other types of waves Infrared waves Carry more energy than microwaves Visible light Can be seen with human eye Contains all colors of light Ultraviolet light Short wavelength Greater energy than visible light
16. Compressional Waves A wave consisting of a periodic disturbance or vibration that takes place in the same direction as the advance of the wave.
