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Homework Help: Mirror question # 2

  1. Dec 12, 2007 #1
    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.

    I also don't know how to do this one either :cry:
     
  2. jcsd
  3. Dec 12, 2007 #2
    -_-" Since the star is really really far away, set the distance of the object from the mirror to be at infinity. Then, draw the diagram. The last time I did these sort of diagrams is when I was 17, so I can't really help you much with the diagram...
     
  4. Dec 12, 2007 #3
    so how exactly do I have to do this T.T...
     
  5. Dec 13, 2007 #4

    rl.bhat

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    Homework Helper

    Light from the star can be taken as a paralllel beam of light. When a parallel beam of light falls on a concave mirror or a convex lens they are brought to focus at the focal length. In the cas of concave mirror focal length = half the radius of curvature.
     
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