Types of Waves

Waves

• A wave is a back and forth motion that carries energy through matter or through space.

Characteristics of a Wave

• The highest points on a wave are called crests.• The lowest points are called troughs.

Characteristics of a Wave

• Wavelength is the distance between one crest or trough to the next.

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.

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.

Two types of waves

• Waves are generally one of two basic types:– Mechanical – Electromagnetic

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

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

Electromagnetic Spectrum

• An electromagnetic spectrum is a range of radiant energy arranged in order of wavelength and frequency.

Radio Waves

• Have some of the longest radio wavelengths of all electromagnetic waves. – Low energy waves.– Radio and Television stations use radio waves.

Microwaves

• Short wavelengths• High frequency• Carry more energy than radio waves• Uses:– Cell Phones– Radars– Microwave ovens

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

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

Compressional Waves

A wave consisting of a periodic disturbance or vibration that takes place in the same direction as the advance of the wave.