http://www.ck12.org Chapter 5. Energy
5.25 Surface Wave
- Define surface wave and give an example.
- Describe the motion of particles of the medium in a surface wave.
- Explain why ocean waves break near the shore.
This immense wall of moving water gives the surfer an amazing ride. The swelling surf raises him up and pushes
him forward as though he’s as light as a feather. All he needs to do is keep his balance on the surfboard. The
incredible power of the wave will do the rest. Ocean waves like this one are examples of surface waves.
Waves on the Surface
Asurface waveis a wave that travels along the surface of a medium. The medium is the matter through which the
wave travels. Ocean waves are the best-known examples of surface waves. They travel on the surface of the water
between the ocean and the air.
Q:What do you think causes ocean waves?
A:Most ocean waves are caused by wind blowing across the water. Moving air molecules transfer some of their
energy to molecules of ocean water. The energy travels across the surface of the water in waves. The stronger the
winds are blowing, the larger the waves are and the more energy they have.
How the Medium Moves
A surface wave is a combination of a transverse wave and a longitudinal wave. A transverse wave is a wave in which
particles of the medium move up and down perpendicular to the direction of the wave. A longitudinal wave is a
wave in which particles of the medium move parallel to the direction of the wave. In a surface wave, particles of the