What Does Each Symbol in the Interference Pattern Equation Represent?

[3nder]

i have a class test tomorrow and I've been studying but i can't find this one equation in the textbook and was looking for some help. I am asked to 'determine the distance between a diffraction grating and a screen by using the interference pattern equation.' this is a practical exam and count towards my HSC so any help is appreciated. thankyou
interference patturn equation: d * l / $$\chi$$ = m $$\lambda$$
i do not know what the symbols stand for as i can't find this equation anywhere but i do know $$\chi$$, $$\lambda$$ and I am assuming 'm' stands for mass.

 

[madmike159]

I thkink:

X is the fringe distance
Lambda is wavelength
l is the length from the diffraction grating to the screen (center)
d is is the separation of the slits
m is mass

Are you sure you have the equation right though? If m is mass this equation would only work for particles with mass such as electrons, not photons which have no mass.

 

[3nder]

yeah that's the one on assessment sheet, everything you said sounds about right. but i don't know what to think about the 'm'
mabey i read it wrong and it's a stylised 'n'

 

[madmike159]

That sounds better, and might explain why you have never found the equation.

This might be what you were after

http://en.wikipedia.org/wiki/Double-slit_experiment#Results_observed