Waves: Not Just the Ocean Variety

In class today, we started our Waves Unit by learning definitions that concern waves.

Wave: a transfer of energy in the form of a disturbance

Mechanical Wave: A wave that requires a medium to pass through (i.e. sound and water waves). For example, there is no sound in space because there is no medium in space.

Electromagnetic Wave: A wave that does not need a medium (i.e. light, radio waves). For example, light needs to be an electromagnetic wave because, otherwise, how does the light from the sun get to the earth?

Matter Wave: A wave concerning electrons and other particles. These particles' behaviours can be predicted because they move in waves.

We also learned about two different kinds of waves.

Transverse Wave: A wave that vibrates perpendicular to the direction of the rest axis.

My favourite example of a transverse wave would be, of course, a guitar string. The following video demonstrates amplitude, wavelength, and the equilibrium position. It also includes some guitar licks, just so you know that I know my stuff.

The example of amplitude is a little hard to see, so before you watch the video, I will explain it. I first pluck one of the strings lightly, causing a decreased amplitude. After, I pluck the string harder and the amplitude increases.




Longitudinal Wave: A wave that vibrates parallel to the direction of the rest axis. An example of this wave would be a spring compressing, like in a pogo stick.

In this wave, compression is the part that is compressed and the rarefaction is the part that is not compressed.


Even though this stuff with waves is very interesting, the most interesting thing that we have learned today was that, no matter how tangled a slinky gets, it can be untangled.