Find the absolute value of theta 650-theta 420

AI Thread Summary
To find the absolute value of theta 650 minus theta 420, the formula d*sin(theta) = m*lambda is used, where d is the grating spacing, m is the order of the maximum, and lambda is the wavelength of the light. Given that the grating has 5000 slits/cm, the spacing d can be calculated as the inverse of the number of slits per centimeter. By substituting the values for each wavelength (650 nm and 420 nm) and the second order maximum (m=2) into the formula, the angles for each wavelength can be determined. The final step involves subtracting the two angles to find the absolute difference. This method effectively calculates the angular separation of the two light rays' second order maximum.
ahazen
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Two rays of light of wavelength 650 nm and 420 nm are normally incident on a different grating. If the grating has 5000 slits/cm, what is the angular separation of of the two light rays' second order maximum.

-Need to find the absolute value of theta 650-theta 420

I know I need to use the formula d*sin(theta) = m*lambda to find each of the angles in degrees -- then subtract

Please help me:):)

Thank you:)
 
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ahazen said:
I know I need to use the formula d*sin(theta) = m*lambda to find each of the angles in degrees -- then subtract
Yes, exactly. What is it that you don't understand? Just plug in the values for d, m, and λ to figure out what θ is.
 


oh, ok:) it makes sense now:) thank you:)
 

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