1. Subscribertalzamir
    Art, not a Toil
    60.13N / 25.01E
    Joined
    19 Sep '11
    Moves
    45044
    30 May '12 08:17
    Making a pile of n coins with a radius of R. Each of the coins is placed so that the center point of the coin is slightly to the right of the coin underneath it. How many coins at least are needed so that seen directly from above, the top coin and the bottom coin don't overlap at all? With n coins available, how far to the right from the bottom coin can the top coin be without making the pile collapse?
  2. Subscriberjoe shmo
    Strange Egg
    podunk, PA
    Joined
    10 Dec '06
    Moves
    7733
    05 Jun '12 00:55
    Originally posted by talzamir
    Making a pile of n coins with a radius of R. Each of the coins is placed so that the center point of the coin is slightly to the right of the coin underneath it. How many coins at least are needed so that seen directly from above, the top coin and the bottom coin don't overlap at all? With n coins available, how far to the right from the bottom coin can the top coin be without making the pile collapse?
    5 coins such that the bottom and top coin don't overlap at all, and with n coins available, the distance the top could be from the bottom is infinite as the harmonic series is divergent.