What is the frequency of an electromagnetic wave if it has a wavelength of 1km (1000m)?

The relationship between the wavelength of light, λ, and the frequency, ν, is

c = \lambda \nu

where c is the speed of light

c \approx 3 \times 10^8\,\frac {meters}{sec}

c = 299 792 458 \,\frac {meters}{sec}

Make sure you use the proper units.

I prefer using the 'traditional' formula v=f\lambda, keeping in mind that electromagnetic waves have the speed of light. :rolleyes:

Jerry, an interesting aside, the speed of light is defined as that, i.e. our definition of meter has been tweaked so that the speed of light is exactly 299792458 m/s

Oh, I see! Thanks Cap! :)

Perito agrees: You say "f", I say "nu"... "traditional?" I thought Nu Lambda was traditional!

Okay, I don't know, but that's how I was taught at school, everything concerning those types of numbers through v=f 'lambda' :p