Intensity in Young's double slit experiment problem.

[IrAlien]

Hello all, I have a problem that requires some knowledge about Young's double slit experiment.

The question is as follows:
Imagine performing Young's experiment with one slit wider than the other so that the intensity passing the wider slit is four times as great as that passing the narrower slit. Assume both slits are still 'thin' and act as line sources and show that I = Inaught.(5+4cos(phi))

I do not know where to start... can anyone give me some tips?

Do I use I=4Inaught.[cos(phi/2)^2] ??

Thanks,
Levi

 

[dimensionless]

You have two sources of electromagnetic waves on a plane. The sources are separated by a given distance. They travel through a given distance through space and illuminate second plane.

What you need to do is find the total amplitude of the two electric fields on the illuminated plane, and then find the irradiance.

 

[IrAlien]

Ok thank you for the help. I _think_ I've got it.

Levi

 

[Arowana]

ummm..cant you use Cosine rule to solve this??

 

[dimensionless]

I'm not sure.

I probably wouldn't use it, but it might be useful.