# Uhf radio wave - determine frequency

1. Jul 21, 2010

### flynostrich08

1. The problem statement, all variables and given/known data
in a certain uhf radio wave, the shortest distance between postions at which the elctric an magnetic fields are zero is .34m. determine the frequency of this uhf radio wave

3. The attempt at a solution

i basically just divided (3x10^8)/.34 = (8.8x10^8) that is c/d=frequency
can anyone tell me if that is the correct way to approach the problem? thanks

2. Jul 21, 2010

### kuruman

Re: waves

How is the "shortest distance between postions at which the elctric an magnetic fields are zero" related to the wavelength?

3. Jul 21, 2010

### flynostrich08

Re: waves

i don't know

4. Jul 22, 2010

### collinsmark

Re: waves

You might want to start by sketching a simple sine wave on a piece of paper. Let y be the vertical axis and t be the horizontal axis.

y = Asin(2πt)

Plot the sine wave for a few periods. Make sure to count how many wavelengths you have drawn. Then count how many times the sine wave crosses the t axis. Compare the two.