# Two wavelengths, max/min at same angle

## Homework Statement

Light goes through two slits 40 mm apart. Does an angle exist at which light of wavelength 440nm has a maximum and light of wavelength 660nm has a minimum?

## Homework Equations

dsin$$\theta$$=m$$\lambda$$1 = maximum
dsin$$\theta$$=(m+ 1/2)$$\lambda$$2 = minimum

## The Attempt at a Solution

I solved for sin$$\theta$$ in each case, so I got:

m$$\lambda$$1 = (m+ 1/2)$$\lambda$$2

$$\lambda$$1 = 660nm
$$\lambda$$=440 nm

Now I'm stuck. Both Ms do not have to be the same, right? So do I have to solve for one of the Ms and stick it into an equation I listed in part 2 above? If so, that's a crazy calculation. Thanks!

Redbelly98
Staff Emeritus
Homework Helper
Correct, the m's can be different. But they must both be integers.

Are the slits really 40 mm apart? That's pretty far for an optical double slit setup.

They're actually 40 nm apart, sorry.

Redbelly98
Staff Emeritus
Homework Helper
Are you sure it's not 40 μm?

ah yes you're right