has units of cycles per second.

Or since they tend to drop the cycles,

you can see this written as just 1 over seconds or seconds to the -1.

Little confusing if you don't know what's going on, but it's not that hard.

So if we want to get some more factor label practice at converting units,

this is a good example.

Let's say we have a wavelength of light and we wanna calculate its frequency.

So the frequency has units of cycles per second.

So that's what we want.

And looking at the wavelength, it's, the wavelength

itself is centimeters per cycle, but looks like we want the cycles to be on top.

So I'm going to put the wavelength upside down, 1 over lambda.

And so that gives us units here of cycles per centimeter,

the inverse of Lambda there.

And then the speed of light, c, can be used to

cancel the centimeters and get us the cycles per second that we're looking for.