Calculate Angles for Diffraction Grating 1st & 2nd Order Maxima

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To calculate the angles for the first and second order maxima of light passing through a diffraction grating with 6000 lines/cm, the equation sin(Theta)m = m(Lambda)/d is used, where d is the distance between grating lines. The calculated value for d is 1.667 x 10^-6 m. For the first order maximum (m=1) with a wavelength of 520 nm, the angle Theta is found to be 22.2 degrees. However, there is a correction needed in the calculations as the wavelength used for the initial calculation was mistakenly 630 nm instead of 520 nm. The discussion emphasizes the importance of correctly applying the formula for different order maxima.
AClass
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Homework Statement



Light with wavelengths of 520 nm and 630nm passes through a diffraction grating that contains 6000 lines/cm.

1) Calcualte the angles for the first and second order maxima that would appear on the screen

Homework Equations



sin(Theta)m = m(Lamda)/d

The Attempt at a Solution



[6000 lines/cm]^-1 = 1.667x10-4 cm/line = 1.667x10-6 m/line

d=1.667x10-6 m

-light 1- m=1

sin(Theta)1=[(1)(5.20x10^-7m)]/[1.667x10-6m]
Theta 1 = 22.2 degrees

Am I on the right track? I just have to for the other 3 situations?
 
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AClass said:

Homework Equations



sin(Theta)m = m(Lamda)/d
That should be:
sin(Theta) = m(Lamda)/d​
No "m" on the left side of the equation. This makes no difference when m=1, but you'll get the wrong answer when m=2.

The Attempt at a Solution



[6000 lines/cm]^-1 = 1.667x10-4 cm/line = 1.667x10-6 m/line

d=1.667x10-6 m

-light 1- m=1

sin(Theta)1=[(1)(5.20x10^-7m)]/[1.667x10-6m]
Theta 1 = 22.2 degrees
It looks like you really used 630 nm, not 520 nm here.
Am I on the right track? I just have to for the other 3 situations?
You're close to the right track, see my comments above.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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