Properties of Waves

- Anything that oscillates/vibrates is an example of a wave.
- Waves transfer energy, not matter/matter.
- The highest point on a wave is the peak; the lowest point is the trough. 
- A wave that oscillates at 90° to the direction it's travelling in is known as a transverse wave, such as a water wave.
- A wave that oscillates parallel to the direction energy is transferred in is known as a longitudinal wave, e.g., sound waves. 
- Wavelength = distance between two identical points on a wave. It has the symbol λ and is measured in meters (m).
- The frequency (f) is measured in Hertz (Hz), which is the number of waves per second.
- Time period (T) = the time it takes for a single complete wave to pass, measured in seconds.
- Amplitude (A) = how much energy is in the wave. Measured from middle to top/bottom.

TRANSVERSE WAVE

Equations

EXAMPLES

1) A tuning fork produces the note C, 262 Hz—what time period does C have?

2) The bottom string has a time period of 0.012s when plucked. What frequency does it produce?

EXAMPLES

1) A person whistles at a pitch of 2000 Hz. The speed of sound in air is 330 m/s. What is the wavelength of the sound wave?

2) A loudspeaker produces a sound with a wavelength of 20 cm. If the speed of sound in air is 330 m/s, what is the sound frequency?