Basic Properties and Behavior of Waves Notes

BASIC PROPERTIES AND BEHAVIOR OF WAVES NOTES

Standard 8.P.3: The student will demonstrate an understanding of the properties and behaviors of waves.

Performance Indicator8.P.3A.2: Develop and use models to exemplify the basic properties of waves (including frequency, amplitude, wavelength, and speed).

PROPERTIES OF A TRANSVERSE WAVE

The highest point of a transverse wave is the crest and the lowest point is called a trough.

Frequency (NUMBER OF WAVES THAT PASSES THROUGH)

• ● Frequency is a measure of how many waves pass a point in a certain amount of time. The higher the frequency, the closer the waves are together and the greater the energy carried by the waves will be.

 Frequency is measured in Hertz or cycles per second. The frequency is often represented by the lower case “f.”

•  The formula for frequency is: f=1/T (T means Time or Period)

• Amplitude (HEIGHT OF THE WAVE)

● Amplitude is a measure of the distance between a line through the middle of a wave and a crest or trough.

● The greater the force that produces a wave, the greater the amplitude of the wave and the greater the energy carried by the wave.

● In a transverse wave the higher the wave, the higher the amplitude.

● Sounds with greater amplitude will be louder; light with greater amplitude will be brighter.

• Wavelength (DISTANCE OF A WAVE FROM CREST TO CREST OR TROUGH TO TROUGH)

1 ● Wavelength is a measure of the distance from the crest on one wave to the crest on the very next wave. 2 ● Shorter wavelengths are influenced by the frequency.

3 ● A higher frequency causes a shorter wavelength and greater energy.

 The wavelength is usually represented by the Greek letter lambda

4 Speed or Velocity of a Wave

5 ● Speed is a measure of the distance a wave travels in an amount of time.

6 ● The speed of a wave is determined by the type of wave and the nature of the medium.

7 ● As a wave enters a different medium, the wave’s speed changes. Waves travel at different speeds in different media. For example: sound travels at different speed in air than in water.

8 ● All frequencies of electromagnetic waves travel at the same speed in empty space.

 The velocity can be found by multiplying the frequency by the wavelength.

RECAP- MOVEMENT OF TRANSVERSE VS. LONGITUDINAL WAVES LABEL THE CREST, TROUGH, AMPLITUDE AND WAVELENGTH OF THE TRANSVERSE WAVE

LABEL RAREFACTION, COMPRESSION AND WAVELENGTH ON THE COMPRESSIONAL/LONGITUDINAL WAVE