Question

If you jiggle a charged comb once per second to create an electromagnetic wave,
a. what is the source frequency?
b. what is the speed of the wave?
c. what is the wavelength of the wave?

Answer 1

I think I'm supposed to use the equation \[c = f \times \lambda \] but I don't know how.

Answer 2

f is the frequency, c is the speed of the wave, and lambda is the wavelength.

Since we're talking about an electromagnetic wave, we're talking about light! Which has a constant speed (for the most part) so since you're told that you jiggle it once per second, then you've got the frequency because it's telling you how frequent you are moving the charge!

So you can solve for the wavelength since they tell you the frequency and you can look up the constant, speed of light.