Transverse waves

A transverse wave is one in which the vibrations of the particles are at right angles to the direction in which the energy of the wave travels.

Demonstrating transverse waves

Transverse waves are often demonstrated by moving a rope rapidly up and down.

A hand holding the left end of a rope. The rope is taut.

1. A hand holds a length of rope taut

In the diagram the rope moves up and down, producing peaks and troughs.

Energy is transferred from left to right at right angles to the hand movement.

However, none of the particles are transported along a transverse wave.

The particles move up and down as the wave is transmitted through the medium.

Examples of transverse waves include:

  • ripples on the surface of water;
  • vibrations in a guitar string;
  • a Mexican wave in a sports stadium;
  • electromagnetic waves – eg light waves, microwaves, radio waves, x-rays;
  • S type earthquake waves.

One way of remembering that an S type earthquake wave is a transverse is that an S looks like a transverse wave on its side.

Illustration showing amplitude and wavelength of S-type wave

Mechanical and electromagnetic waves

Mechanical waves cause oscillations of particles in a solid, liquid or gas and must have a medium to travel through – they cannot pass through a vacuum.

Electromagnetic waves cause oscillations in electrical and magnetic fields and can travel through a vacuum.

All waves transfer energy from one place to another, but they do not transfer matter.