Properties of Waves

Describing a wave

• Amplitude: the maximum displacement of a point on a wave away from its undisturbed position. It is measured from the middle line to a peak, not from peak to trough
• Wavelength ($\lambda$): the distance from a point on one wave to the equivalent point on the adjacent wave, for example peak to peak. Unit: metres, m
• Frequency ($f$): the number of waves passing a point each second. Unit: hertz, Hz. 1 Hz is one wave per second; 1 kHz = 1000 Hz
• Period ($T$): the time for one complete wave to pass a point, in seconds. Period and frequency are linked (on the equation sheet):

$$T = \frac{1}{f}$$

• Worked example: a wave with a frequency of 50 Hz has a period of $\dfrac{1}{50} = 0.02$ s
• Wave speed ($v$): the speed at which the energy is transferred (or the wave moves) through the medium. Unit: m/s