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## Homework Statement

Using the two-dimensional wave interference pattern shown and the two equations involving path difference, complete the following:

(please see attachment)

a)Measure the wavelength of the waves, the distance between the sources, and the path distance from each of the sources to point P.

b)Choose a point on any antinodal line and

**show the complete calculation for wavelength**.

c)What effect would an increase in frequency have in the interference pattern?

d)What effect would decreasing the distance between the wave sources have on the interference pattern?

e)If the phase of the vibrating sources were changed so they were vibrating completely out of phase, what effect would this have on the interference pattern?

## Homework Equations

|PnS1-PnS2|=(n-1/2)W

|PmS1-PmS2|=mW

where W=wavelength

## The Attempt at a Solution

all approximated (measured with a ruler)

W= 7mm

dS1S2=23mm

PnS1=62mm

PnS2=81mm

|PnS1-PnS2|=(n-1/2)W

|62-81|=(1-1/2)W

-19=(1/2)W

W=-38 ?

All I need is a bit of direction here on part a and b. The textbook is confusing with the examples it provides and I find this question confusing as well. After I measured the wavelength, it wants me to find the wavelength using the measured wavelength? What am I trying to find? My answer is obviously way off and substituting n=2 only gives me -12.6 for W. After I measure the wavelength, what then?

any help on this question is appreciated, thank you