Angular seperation between diff wavelengths

AI Thread Summary
To find the angular separation between refracted blue (480nm) and red (670nm) light in glass, apply Snell's law using their respective indices of refraction (1.4636 for blue and 1.4561 for red) and the angle of incidence (80 degrees). Calculate the angle of refraction for each color: blue light refracts at approximately 81.13 degrees, while red light refracts at about 81.03 degrees. The angular separation is determined by subtracting the angle of refraction for red from that of blue, resulting in an angular separation of 0.10 degrees. This calculation illustrates how different wavelengths of light bend differently when passing through a medium. Understanding this concept is crucial for studying light behavior in various materials.
Dx
A ray of light consists of blue light(480nm wavelength) and red light(670nm wavelength) is incident on a think piece of glass at 80 degrees. what is the angular separation between the refracted red and blue beams while they are in glass? (The respective indices of refraction for the blue light and red light are 1.4636 and 1.4561)

What in the hell do I do?

I have got no clue what to do here, please help. Lost soul here with lots of determination to learn without using a lot of math. HEHEHE!
Any help would be appreciated!
Thanks!
Dx :wink:
 
Physics news on Phys.org
Just treat it as two different problems. If you have monochromatic light incident on a surface at an angle θi, how do you calculate the angle of refraction θr? Do that for both cases, and subtract the two angles to find the angular separation.
 

Hi there! Don't worry, I can help you out with this problem.

First, we need to understand what angular separation means. Angular separation is the angle between two rays of light after they have been refracted (or bent) by a medium, in this case, the glass.

To find the angular separation between the red and blue beams, we need to use Snell's law, which states that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is equal to the ratio of the speed of light in the first medium to the speed of light in the second medium.

In this case, we have the angle of incidence (80 degrees) and the indices of refraction for the blue and red light. We can use these values to find the angle of refraction for each beam.

For the blue light:
sin(80 degrees)/sin(angle of refraction for blue) = speed of light in air/speed of light in glass
sin(angle of refraction for blue) = sin(80 degrees) * speed of light in glass/speed of light in air
sin(angle of refraction for blue) = sin(80 degrees) * 1.4636/1
sin(angle of refraction for blue) = 0.9946
angle of refraction for blue = 81.13 degrees

For the red light:
sin(80 degrees)/sin(angle of refraction for red) = speed of light in air/speed of light in glass
sin(angle of refraction for red) = sin(80 degrees) * speed of light in glass/speed of light in air
sin(angle of refraction for red) = sin(80 degrees) * 1.4561/1
sin(angle of refraction for red) = 0.9927
angle of refraction for red = 81.03 degrees

Now, we can use these angles to find the angular separation between the two beams. We simply subtract the angle of refraction for red from the angle of refraction for blue.

Angular separation = 81.13 degrees - 81.03 degrees = 0.10 degrees

So, the angular separation between the refracted red and blue beams while they are in glass is 0.10 degrees.

I hope this helps! Feel free to ask for clarification if you need it. Keep up the determination to learn, you got this!
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top