How far is the image of the star from the concave mirror?

AI Thread Summary
The problem involves calculating the distance of the star's image from a concave mirror with a radius of curvature of 1.70 m, resulting in a focal length of 0.85 m. The light from the star is treated as coming from infinity, which simplifies the object distance (do) to infinity. Using the mirror formula 1/di + 1/do = 1/f, with do as infinity, leads to the conclusion that the image distance (di) is equal to the focal length. Therefore, the image of the star is located 0.85 m from the surface of the mirror. This approach effectively resolves the initial confusion regarding the distances involved.
leehom
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Homework Statement



The light from a star reflects from a concave mirror with a radius of curvature of 1.70 m. Determine how far the image of the star is from the surface of the mirror.

Speed of light = 3.0 x 10^8 m/s
r = 1.7 m
f = 0.85 m

1/di + 1/do = 1/f... and then I'm stuck b/c i don't know what di or do are
 
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A stars light is considered as coming from infinity.
 
Okay... but that doesn't help me solve di or do...
 
Well the star is the object isn't it. So the object distance is infinity.
 

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