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Jellybean jar problems

  1. Jan 24, 2007 #1


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    I've been very interested in these since an hour ago, and would like to figure out a few I have devised.

    To solve the problems one estimates how many of a geometrical object will fill a cavity in practice. You might be able to find how many melted jelly beans can fit in a jar, but that's not the same as real ones.

    The first one I thought of was an oddly shaped jar.

    It is a truncated ellipsoid, with dimensions 10" high, 7" at widest, and 4.75" thick. Where is it truncated? Part of it was lopped off, leaving a straight edge that goes halfway up to the equator of it, the top and bottom, and left and right sides were lopped off as well. The flat side on the top and bottom, and the flat side on the left and right are the same.

    The third one is a box, which is 10x10x3 inches.

    Now, how can we find how many of (the classic) jellybeans can be poured in, making sure to take into account empty space inbetween units? But for an added twist, what about tiny 1x1x1 cm cubes, or Hershey's kisses?
  2. jcsd
  3. Jan 26, 2007 #2
    Calculating how many beans can be poured in is impossible; there's an infinite number of ways jellybeans could be arranged in the container. However, if you divide the number of jellybeans by the volume of the container, the result should always be around some value. So it would be best to remember that constant and multiply it by the volume of the container. It'd be interesting to make a Gaussian Curve out of that.
  4. Jan 26, 2007 #3
    I can see it's time to give up my career and dedicate myself to finding the gausian distribution of jelly bean packing dynamics. :-)
  5. Jan 31, 2007 #4


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    I think I'll do that!!
  6. Jan 31, 2007 #5
    Yeah, but it's not impossible to find the number of ways to fit the most number of jellybeans or whatever in the jar.
  7. Jan 31, 2007 #6
    But is the question, how to maximise jelly bean packing density in an irregular container, or how many randomly packed jelly beans are present in full irregular container.

    In the 1st you can work out the optimum packing pattern but would probably never be able to build a machine to pack in that pattern.

    In the 2nd there will always be a random element dictating packing efficiency.

    Unless the maximum variation in packing efficiency equates to less than the volume of a soingle bean there will always be an ambiguity in the answer.
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