2 WavesA wave is a disturbance that carries energy through matter or space.It does not move matter.Energy may spread out as a wave travels.
3 Types of Waves Mechanical Waves – waves that require a medium A medium is a material that the wave moves through.Stone thrown in a pondSound from a stereoEarthquake
4 Types of WavesElectromagnetic Waves – waves that do not require a mediumLight through spaceRadio wavesRadar
5 Transverse & Longitudinal Waves Transverse waves – waves in which the motion of the particles is perpendicular to the motion of the wave.Waves in a ropeLongitudinal waves – waves in which the motion of particles is parallel to the direction of the waveSound wavesSimulation
6 Characteristics of Waves Wavelength – the distance between two similar points on a wave
7 Characteristics of Waves Amplitude – measured the amount of particle vibration or the height of the wave – half the height of the wave.
8 Characteristics of Waves Frequency – measures the rate of vibrationsAs frequency increases the wavelength decreases.
9 Electromagnetic Spectrum The electromagnetic spectrum shows all the different types of electromagnetic waves (transverse).The higher the frequency, the more energy it has.They all travel at the speed of light.
11 Wave SpeedThe speed of a wave depends on the material it is passing through.The denser the material, the faster a mechanical wave will move through it (sound travels 3 – 4 times faster through water than air)Example: Door, Train TracksA dense material will slow down an electromagnetic wave (light travels slower through glass than air)
12 Wave SpeedMechanical waves travel fastest through solids and slowest through gasses.Transverse waves travel fastest through gasses and slowest through solids.
13 Doppler Effect Doppler Applet The Doppler effect is a change in the observed frequency of a wave resulting from the motion of the source or observerWaves are compressed as the sound source comes toward you producing a higher pitched sound. When it travels away the waves are farther apart producing a lower pitched soundThis occurs in both sound and light.Doppler Applet
14 Characteristics of Waves Higher the frequency the greater the energy.Lower the frequency the lower the energy.Human hearing: 20 Hz to 20,000 HzDog hearing: 40 Hz to 46,000 Hz