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Homework Help: Images and Lenses (explanation needed please)

  1. Sep 17, 2005 #1
    Okay, so I have to do a Lab Report, easy enough, I've done them before, but it isn't so clear, and when I tried doing it, I wasn't sure if I was even doing it right.


    Anyway, here's what I have to do.

    The Lab Report is on the relationship between the image distance and the object distance for real images in a converging lens. These are the ONLY instructions they give me.

    In a semi-darkened room, line up a lighted candle, a convering lens, and a screen. Hold the lens between the candle and the screen, so that the distance from the candle to the lens is about twice the estimated focal length of the lens. Hold the screen on the other side of the lens about the same distance away from the lens: that is at about 2f. Move the screen back and forth until a sharply focused image of the candle appears.

    Now, my problem is...is it the image of the candle I'm looking for? (which seems highly unlikely) or the FLAME of the candle?
  2. jcsd
  3. Sep 17, 2005 #2
    it says the candle so i would assume the candle is what they meant
  4. Sep 18, 2005 #3


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    Homework Helper

    You can form a real image of anything you can see, but things that emit light are going to be easier to see than things that only reflect light. When you form the image of the candle, the image of the flame will be easier to see and to work with. Within the limits of your lab, I wouldn't worry over much about the difference - for practical purposes, the image of the flame is the image of the candle.
  5. Sep 18, 2005 #4
    Thanks very much for clearing that up
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