Double Slit experiments

1. Feb 4, 2017

Noriko Kamachi

1. The problem statement, all variables and given/known data
A double-spit experiment is performed with light of wavelength 600 nm. A wide viewing screen is 2m behind the grating. What is the distance between the two m=2 bright fringes on the screen? The slit separation given is 0.1 mm.

2. Relevant equations
Given the wavelength and distance I am assuming y = mλL/d makes the most sense for the equation to solve this problem.

3. The attempt at a solution
I make d=(.1*10^-3)
Wavelength given=600 nm so I make that (600*10^-9)
and my distance and screen are both 2 so I enter the equation as:
y=((2)(2)*(600*10^-9)/(0.1*10^-3)
= (2.4*10^-2) mm as my solution. It looks weird as an answer though. Did I tackle this problem correctly?

2. Feb 4, 2017

kuruman

What are the units for d and all the other numbers you calculated? Why do you say the final answer is in mm?

3. Feb 4, 2017

Noriko Kamachi

d is the distance so its unit would be m and i assumed the final answer would be nm because I would be measuring the final distance in terms of wavelength?

4. Feb 4, 2017

kuruman

In this equation, put units next to each number and see what comes out.