Young's Modulus Experiment With a Glass Screen

[Jeremy Feng]

Homework Statement

Homework Equations

Path difference is nλ at maxima, (n+0.5)λ at minima

The Attempt at a Solution

I think the phase difference between S1 and S2 is not 0 anymore, because the wave effectively takes a longer distance by going through S2. Thus, there is no longer a central maxima at O.

This means the whole fringe pattern shifts, however why is it towards Y?

 

[J Hann]

Consider the number of wavelengths of the light as it passes thru the glass
as compared to the number of wavelengths of light as it passes thru
an equivalent thickness of air.