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Homework Help: A tree and a mirror on the ground

  1. Jul 12, 2012 #1
    1. The problem statement, all variables and given/known data

    A plane mirror made of a very thin piece of glass lies flat on the ground. As shown in the following figure, one end of the mirror is 2.1 m from you and the other end is 35 m from a nearby tree. You are 1.6 m tall, and the mirror has a length L. The mirror is arranged so that you can just see the image of the top of the tree at one edge of the mirror. how tall is the tree?

    2. Relevant equations

    I know you have to use the principle of similar triangles

    3. The attempt at a solution

    I tried using height of person/distance of person from mirror = height of tree/distance of tree from mirror . This is similar to a problem our TA did in class and I thought I was using the correct formula, however, I have been unable to get the correct answer and I dont understand what Im doing wrong and only have one attempt left for credit
  2. jcsd
  3. Jul 12, 2012 #2
    Any chance you could show the figure?

    What edge does he see the top of the tree? the edge that is closer to the man, or the edge that is closer to the tree?

    I believe you answer will be in terms of L. Unless L has a value?
  4. Jul 12, 2012 #3


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