Question

If you could really explain this problem to me I'd be super grateful! Calculate the wavelength of radio waves broadcasting at 550nm.
(here's where I get confused) The book gives 2 formulas. One is for the average speed of sound IN SOFT TISSUE OR WATER (1500m/s). The other is for the speed of light (3E8m/s). The radio waves are being broadcasted, so I'm not sure which one to use.

Answer 1

what do you mean by 550nm ?

Answer 2

With one you're dealing with sound, and the other electromagnetic radiation. The formula that has a "c" in it is the one you need. Make sure you convert nm to meters - Googlable.

You might want to Google e m spectrum as well.

Answer 3

I don't think you can have typed out the question correctly, as it stands it doesn't make sense to me, please check.

Answer 4

Use the formula that uses the speed of light, both radio waves and light waves travel at the same speed. However, that is a pretty short radio wave (550nm). I take that is nanometer and is a very short wavelength.

Answer 5

I looked up the average speed of radio waves and found that it's the same as light. I did the formula (correctly as far as I know) and got 250000meters

Answer 6

What I don't understand, it is asking you what wavelength the radio is broadcasting on and then tells you the wavelength. Maybe that is supposed to be broadcasting at a frequency of 550 KHz ??

Answer 7

As ProfBrainstorm suggested ensure you have copied it correctly.

Answer 8

whoa, so sorry you guys! The waves' frequency is 1200KHz. I apologize *blushes*

Answer 9

Wavelength is velocity divided by frequency, what did you get for wavelength?

Answer 10

3E8=1200KHz (wavelength)
so I divided both sides of the equation by 1200 and got 250000m, but that seems large for a radio wave.