Electromagnetic Spectrum
Wave Properties
Radio Waves
Reflection and Refraction

Other Sections


Properties of Waves

A Wave

labeled diagram of a wave

Above is a displacement / distance graph showing a wave. It is labeled with some key terms

Amplitude is the height of the wave from 0 displacement (normal) to the peak, where the peak is the highest point. The Wavelength is the distance from the start to the second point the wave passes 0. i.e. a complete wave.

Period: if it was a displacement/time graph, the period would be equivalent to wavelength, so period is the time for the wavelength. The frequency is 1 / period and measured in Hz (1Hz = 1wave per second).

The Wave Equation

the wave equation

Have a look at the examples using this equation, below.

A loundspeaker reproduces a note of frequency 320Hz. It travels through the air with a speed of 340ms-1.
a) What is the wavelength in air?

l = v/f
l = 340ms-1 / 320Hz
l = 1.06m

b) The sound passes through water where its wavelength is 4.5m.
Calculate the speed of sound in water

V = fl
V = 320Hz x 4.5m (frequency doesn't change)
V = 1,440ms-1

Types of Wave: Transverse or Longitudinal?

There are two basic types of wave. They are

The oscillation/vibration is at right angles to the direction of travel. An example of transverse waves are electromagnetic waves

an example of a transverse wave using a rope

Longitudinal Wave
The oscillations/vibrations are along the line of travel.
Are mechanical waves because it actually moves particles. E.g. sound waves.

an example of a longitudinal wave