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Homework Help: Brittanica on a Pinhead

  1. Aug 31, 2009 #1
    1. The problem statement, all variables and given/known data
    Richard Feynman propsed writing the entrie Encyclopaedia Brittanica on the head of a pin.
    1) Estimate the size of the letters needed if we suppose a pinhead is 1/16 in across.
    2) If the atomic spacing is 5x10^(-10)m, how many atoms across is each letter?

    2. Relevant equations

    3. The attempt at a solution
    So I assume that the average Britannica contains 50 million words, but what I need is the average areas of a pinhead compared to Britannica (which I can't figure out how to get values of).
    I've also estimated the answer to be 10^(-8) atoms from some articles I have read, but I unfortunately can't come up how to get that solution.

    A little help please? It's due tomorrow morning
  2. jcsd
  3. Aug 31, 2009 #2


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    Gold Member

    Re: [Urgent] Brittanica on a Pinhead

    Welcome to Physics Forums.

    You are given the size of the pinhead, assuming that it is circular, you can then determine the area of the pin head.

    The next step is then to estimate the average number of letters in a word - such things are undoubtedly available on the internet.
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