How Does Changing Slit Separation Affect Wavelength in a Two-Slit Experiment?

[conniechiwa]

Homework Statement

An optical two-slit experiment is setup with its slits separated by 40 X 10-3 cm and produces a second order maximum at an angle of 0.09 degrees. What would the wavelength of the light need to be if we kept the position of the second order maximum the same, but increased the slit separation of 63 X 10-3 cm?

Homework Equations

wsinϑ=mλ

The Attempt at a Solution

630000nm*sin0.09=2λ
λ=494.8nm

I'm almost positive that this is right, but the system won't accept my answer. Please help me!

 

[Kurdt]

I agree with you. Does the system want it in any other units?

 

[Redbelly98]

Two things occur to me:

1. Do they mean the final slit separation is 63 X 10-3 cm, or is that amount to be added to the original 40 X 10-3 cm?

2. Perhaps they are expecting an answer rounded to the nearest 1 nm?

 

[conniechiwa]

It asks for the answer in nm. I tried adding the final slit separation to the original and it didn't work either.

 

[Redbelly98]

"63 X 10-3 cm" is a rather odd way to express a number or distance, since it's not proper scientific notation. You might double-check that this is actually what they say in the problem statement.

Proper scientific notation would be (for example)
6.3 x 10-2 cm.

 

[conniechiwa]

Yeah it says 63 X 10-3 cm. I copied and pasted the question.

 

[Doc Al]

but increased the slit separation of 63 X 10-3 cm?

That highlighted word doesn't seem correct. Is it "to" or "by", by any chance?

 

[conniechiwa]

No, it's "of".

 

[Doc Al]

Is this from a textbook?

 

[conniechiwa]

It's online homework. Maybe it's glitched.

 

[Mrharlin]

the equation you are looking for is;
sin\theta=n\lambda/2d

\lambda=(2d)sin\theta/n

"two-slit experiment is setup with its slits separated by 40 X 10-3 cm"
--this being two-slit means it is 2d

 

[Doc Al]

the equation you are looking for is;
sin\theta=n\lambda/2d

\lambda=(2d)sin\theta/n

"two-slit experiment is setup with its slits separated by 40 X 10-3 cm"
--this being two-slit means it is 2d

All you've done is taken the standard formula and renamed the slit separation 2d instead of the usual d.