1. Notes 2: Wave Properties
Chapter 10 Section 2 (page 296)

2. What You’ll Learn Define wavelength, frequency, period, and amplitude.
Describe the relationship between frequency and wavelength.
Explain how a wave’s energy and amplitude are related.
Calculate wave speed.

3. Why It’s Important
Waves with different properties can be used in different ways.

4. Review Vocabulary
Vibration - a back and forth movement.

5. The Parts of a Wave
What makes sound waves, water waves, and light waves different from each other? It’s their characteristics that make them unique.
These characteristics include:
The type of mechanical wave (transverse or compressional)
Wavelength
Frequency and Period
Wave Speed
Amplitude and Energy

6. Differences between Transverse and Compressional Waves
The transverse wave has alternating high points, called crests, and low points, called troughs.
A compressional wave has no crests and troughs. Instead, it creates regions where the medium becomes crowded together, called compressions, and regions where the medium becomes spread apart, called rarefactions.

7. Wavelength
Wavelength - distance between one point on a wave and the nearest point just like it.
A wavelength in a transverse wave is the distance between two two crests.
A wavelength in a compressional wave is the distance between two neighboring compressions.

8. Frequency and Period
Frequency - the number of wavelengths that pass a fixed point each second; is expressed in hertz (Hz)
You can find the frequency by counting the number of crests or compressions that pass every second.
Period - the amount of time it takes on wavelength to pass a fixed point is expressed in seconds.
You can find the period by counting the number of seconds between each crest or compression.

9. Wave Speed
If you use a rope to make transverse waves, you can increase the frequency by moving the rope up and down faster. Moving the rope faster also makes the wavelength shorter.
The speed of a wave takes into account the frequency of the vibration and the wavelength of the wave.

10. Calculating Wave Speed
The speed of a wave depends on the medium in which the wave travels and can be calculated using this equation:
V = f λ
Velocity (m/s) Frequency (Hz) Wavelength (m)

11. Amplitude and Energy
Amplitude - a measure of the energy carried by a wave.
The amount of energy a wave can carry varies. The greater the amplitude, the greater the energy.

12. Summary
Transverse waves have repeating high points called crests and low points called troughs.
Compressional waves have repeating high-density regions called compressions, and low-density regions called rarefactions.
Wavelength is the distance between a point on a wave and the nearest point just like it.
Frequency is the number of wavelengths passing a fixed point each second.
Period is the amount of time it takes one wavelength to pass a fixed point.
The speed of a wave depends on the medium it is travelling in.
The wave speed equation is: v = fλ.
As the amplitude of a wave increases, the energy carried by the wave increases.