Waves and wave motion

What are waves? They can be described briefly as disturbances in a medium which transfer energy and information from point A to point B.^* The key fact is that no physical object actually travels from point A to point B --- and yet both energy and information make the trip.

^* Yes, yes, light waves require no medium and can travel through a vacuum. They are a special case.

• Why study waves?

As we will see, the mathematical description of waves should look very familiar to you, now that you have been studying simple harmonic motion. The major difference is that while SHM involves functions of time

 
y(t) = A cos(ωt)

waves involve functions of both time and space

 
y(x,t) = A cos(kx - ωt)

• Waves and SHM

Ready to try a problem involving a wave?

• An earthquake hits LA!

For more information

• Notes on wave motion
• Seismic waves and the earth's interior

One very common type of wave occurs when a long, thin wire or cord is stretched under some tension, and then jiggled, or plucked, or perturbed.

• Waves travelling on a string
• Challenge: Waves racing up and down a hanging rope

In case we have time ...

• A couple of wave-motion problems

Copyright © Michael Richmond. This work is licensed under a Creative Commons License.