Question

Describe what happens when a wave transfers energy

Answer 1

ARTICLE

 

Waves as energy transfer

‘Wave’ is a common term for a number of different ways in which energy is transferred:

In electromagnetic waves, energy is transferred through vibrations of electric and magnetic fields.In sound waves, energy is transferred through vibration of air particles or particles of a solid through which the sound travels.In water waves, energy is transferred through the vibration of the water particles.

Waves transfer energy but not mass

When we watch surf waves coming into shore, it’s easy to think that individual water particles are moving towards us, but that’s not actually the case. The particles involved in waves move back and forth perpendicularly to the way the wave is going, but don’t move significantly in the direction of the wave. The particles ‘take part’ in the wave by bumping into one another and transferring energy. This is why energy can be transferred, even though the average position of the particles doesn’t change.

Particles in a water wave exchange kinetic energy for potential energy

When particles in water become part of a wave, they start to move up or down. This means that kinetic energy (energy of movement) has been transferred to them. As the particles move further away from their normal position (up towards the wave crest or down towards the trough), they slow down. This means that some of their kineticenergy has been converted into potential energy – the energy of particles in a wave oscillates between kinetic and potential energy.

Measuring the energy in a wave

Why do some waves have more energy than others? A wave’s frequency and wavelength are both indicators of its energy, but this differs for different types for waves.