# Two wavelengths, max/min at same angle

#### cashmoney805

1. 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?

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

3. 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!

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#### Redbelly98

Staff Emeritus
Science Advisor
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.

#### cashmoney805

They're actually 40 nm apart, sorry.

#### Redbelly98

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

#### cashmoney805

ah yes you're right

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