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Old 06-06-2011, 02:39 AM   #1
DrCeshing

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Oct 2005
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Default Stuck on a physics question
If anyone could help me out with this i would appreciate it (and show the work)

"A scientist notices that an oil slick floating on water when viewed from above has many different rainbow colors reflecting off the surface. She aims a spectrometer at a particular spot and measures the wavelength to be 750 (in air). The index of refraction of water is 1.33."

The index of refraction of the oil is 1.20. What is the minimum thickness of the oil slick at that spot?
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Old 06-06-2011, 04:32 AM   #2
LSg44PDu

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If anyone could help me out with this i would appreciate it (and show the work)

"A scientist notices that an oil slick floating on water when viewed from above has many different rainbow colors reflecting off the surface. She aims a spectrometer at a particular spot and measures the wavelength to be 750 (in air). The index of refraction of water is 1.33."

The index of refraction of the oil is 1.20. What is the minimum thickness of the oil slick at that spot?
I haven't had refraction in some time, but if I recall correctly:

Using the formula 2*thickness*Index of Refraction=Wavelength

So,
2*t*n(oil)=lambda, solving for t:

t=lambda/(2*n(oil))

t-312.5nm

I got a B in modern physics, so take my answer with a grain of salt.

I'm a structural and soil guy.
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Old 06-06-2011, 06:14 AM   #3
DrCeshing

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I haven't had refraction in some time, but if I recall correctly:

Using the formula 2*thickness*Index of Refraction=Wavelength

So,
2*t*n(oil)=lambda, solving for t:

t=lambda/(2*n(oil))

t-312.5nm

I got a B in modern physics, so take my answer with a grain of salt.

I'm a structural and soil guy.
thank you for taking the time to reply, it was correct. And the reason i wanted to see the work if you are wondering is that i have some other problems that are similar and i would like to be able to do those on my own now that ive seen one solved out.
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