Waves - 6.1.1 Transverse and Longitudinal Waves (GCSE Physics AQA)
Transverse and Longitudinal Waves
Types of Waves
- There are 2 types of waves. The two types of waves that you need to know for AQA exams are called transverse waves and longitudinal waves. These two types of waves are slightly different in the way that they move.
- Direction of oscillations are different. Both the transverse and longitudinal waves have different directions of oscillations. Transverse waves will have oscillations perpendicular to the direction of travel. Longitudinal waves will have oscillations parallel to the direction of travel, as shown in the diagram.
- Use letters to remember oscillations. In order to remember these oscillations, use the letters ’t’ and ‘l’. If a wave is transverse, remember the letter ’t’, since the direction of the wave is perpendicular to the oscillation. If a wave is longitudinal, remember the letter ‘l’, since the direction of the wave is parallel to the oscillation. Let’s look at the following diagram.
Transverse Waves
- Ripples are transverse waves. On the surface of the water, ripples can form. These are transverse waves. This is because the oscillation of the waves is perpendicular to the direction of travel.
Longitudinal Waves
- Sound waves are transverse waves. Sound waves can be produced from speakers, from our voices or even from the electromagnetic spectrum in the form of ultrasound waves. These are all transverse waves, since the oscillation of the waves is parallel to the direction of travel.
- Compression and rarefaction form these waves. Longitudinal waves are formed of areas of compression and rarefaction. In areas of compression, the crests of the waves are very close together. In areas of rarefaction, the crests of the waves are quite far apart. We can see this in figure 2.
Wave Travel
- Matter is not transferred. When waves are formed, matter doesn’t travel. If we think of the examples of sound waves and ripples on water, we know that the air and the water are not transferred.
- Energy is transferred. Instead of matter being transferred, energy will be transferred. This means that the particles in the air and water will remain where they are, but energy will be transferred between them. This means that the wave itself is the ‘thing’ that travels, not the air or water.
In physics, waves are disturbances that propagate through a medium or space, carrying energy without necessarily carrying matter.
Transverse waves are waves where the displacement of the medium is perpendicular to the direction of wave propagation, while longitudinal waves are waves where the displacement of the medium is parallel to the direction of wave propagation.
Examples of transverse waves include waves on a string, electromagnetic waves such as light, and seismic waves such as S-waves.
Examples of longitudinal waves include sound waves and seismic waves such as P-waves.
The wavelength of a wave is defined as the distance between two consecutive points on the wave that are in phase, such as two crests or two troughs.
The amplitude of a wave is the maximum displacement of the medium from its rest position.
The frequency of a wave is the number of complete cycles of the wave that pass a given point in one second, and is measured in hertz (Hz).
The speed of a wave is equal to the product of its frequency and wavelength, v = fλ.
Waves transfer energy by causing a disturbance in the medium or space through which they propagate. This disturbance creates oscillations in the medium or space, which in turn result in the transfer of energy.
The speed of a wave is affected by changes in the medium through which it propagates. For example, the speed of a wave in a solid medium is generally greater than the speed of a wave in a liquid or gas medium.
Still got a question? Leave a comment
Leave a comment