Understanding Light, Lenses, and Mirrors: Final Exam Review

AI Thread Summary
The discussion focuses on three key physics questions related to light, lenses, and mirrors. When the angle of incidence equals the critical angle, the angle of refraction is 90 degrees. If a screen is moved three times the distance from a light source, the intensity will be reduced to one-ninth of its original value. For a ray of light incident at 38º on a curved mirror, the reflected ray will also leave at an angle of 38º, following the law of reflection. Understanding these concepts is crucial for the final exam preparation.
dranseth
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Homework Statement


I have a final tomorrow, and I there are a couple questions that I don't know.

When the angle of incidence is the critical angle, the angle of refraction will be?

If a screen is moved 3 times the distance from a light source, what will the intensity on the screen be reduced to?

A ray of light is incident at 38º on a curved mirror. At what angle will the reflected ray leave the mirror?


Homework Equations



n1sin90º=n2sin(critical angle)
I'm not sure which formula to use for the one regarding light intensity, and for the last, I drew it out.
 
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90 degree [according to the definition of critical incident angle]

2. don't know

3. 38 degree [ according to the laws of reflection of light: the reflected angle is equal to the incident angle]
 

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