# Homework Help: Vibrating in opposite phase

1. Apr 8, 2005

### SwAnK

hey, i need some help for this question/

Question: A wave passes by two little decoy ducks which are vibraing in opposite phase. They are 1.5m apart. ive two possible wave lengths for this situation.

So im guessing you have to make up a frequency and velocity, so i was gonna use 1000Hz and velocity of 10m/s, to make things easier. Also, since its in opposite phase isnt that half a wavelength?

also does anyone know the standard intensity of a standard earthquake??

Last edited: Apr 8, 2005
2. Apr 8, 2005

### Quantum Cat

Draw a picture of the wave, it'll make things easier. And yes, if they are exactly out of phase, they're half a wavelength apart (or 3/2 wavelengths, or 5/2, etc) since the question probably wants you to find largest possible wavelength (since it could get infinitely smaller) all you have to do is double the distance. The frequency and velocity don't mater, because that only changes how fast they are oscillating! Draw a picture, that'll help you see what I mean.

3. Apr 10, 2005

### SwAnK

thanx alot quantum cat, drawing it does help too! but the wavelength would be 1and3/4, not 3/2? if there out of phase.

Last edited: Apr 10, 2005