1. Jul 25, 2011

### Punkyc7

Two radio antennas A and B radiate in phase. Antenna B is a distance of 130 m to the right of antenna A. Consider point Q along the extension of the line connecting the antennas, a horizontal distance of 50.0 m to the right of antenna B. The frequency, and hence the wavelength, of the emitted waves can be varied.

What is the longest wave lenght that cause constructive interference and what is the longest wavelenght that cause destructive interference

r1-r2=(.5+m)$\lambda$
r1-r2=(m)$\lambda$

After a drew my picture I got r1 =180 and r2=50
then I plugged into the formulas

130=.5$\lambda$ destructive=260
130=$\lambda$ constructive

Is that right because the problem seems to easy?

Last edited: Jul 25, 2011
2. Jul 25, 2011

### ehild

It is that easy but do not forget to add the unit of wavelength to your result.

ehild