Waves

In GCSE physics curriculum, there are two types of shock waves: **P – waves **and **S – waves**. Differences in the speed of P – and S- waves can be used to give evidence for the structure of the Earth.

Waves are regular patterns of disturbance that transfer **ENERGY **in the direction the wave travels without transferring matter- there are two types of **LONGITUDANAL **and **TRANSVERSE**.

**LONGITUDANAL WAVE **– Each particle moves backwards and forwards in the same plane as the direction of wave movement. Each particle simply vibrates to and from about its normal position.

**TRANSVERSE WAVE** - Each particle moves up and down at right angles (90˚C) to the direction of wave movement. Each particle simply vibrates up and down about its normal position.

In GCSE physics, the **distance travelled by a wave **can be worked out using the formula:

**Distance (metres) = Wave speed (metres per second m/s) x Time (seconds)**

All **waves **have several important features:

**Amplitude**– The maximum disturbance caused by a wave. It is measured by the distance from a crest or trough of the wave to the undisturbed position.**Wavelength**– The distance between corresponding points on two adjacent cycles.**Frequency**– the number of waves produced in one second. Frequency is measured in**hertz**(**Hz**).

Wave speed, frequency and wavelength are related by the following formula mentioned in GCSE physics curriculum:

**Wave speed (metres per second, m/s) = Frequency (hertz, Hz) x Wavelength (metres, m)**

For a constant wave speed, the wavelength is **INVERSELY PROPORTIONAL **to the frequency

End of this topic!

Drafted by Gina (Physics)