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    Re: horizon visibility puzzle
    From: Aubrey O´Callaghan
    Date: 2001 Jun 20, 2:28 PM

    Basically this is a distance to horizon problem:
    On the 777 m hill you can see:
    1.144 sqrt( 777*3.281) = 57.76 n. miles
    On the 401 m hill you can see
    1.144sqrt(401*3.281)= 41.5 n miles
    now hills are 35 km apart 35/1.8=19.44 n. miles
    If 777 and 401 m hill were at same place the difference in distance viewed
    would be 16.26 n miles
    If we move 401 m hill forward 16.26 n miles we can both see the same point.
    Therefore this is the line cutting both top of both hills to horizon.
    But we have moved it forward 19.44 n .miles so 401 hill will block 777 hill.
    We cannot see the ocean from 777 hill due to presence of 401 hill.
    At 03:17 PM 20-06-01, you wrote:
    >You are ashore, 777 meters above sea level, looking toward the ocean.
    >In your line of sight, 35 kilometers away, is a hill 401 meters high.
    >Can you see the ocean over the top of this hill?
    >This is an actual question someone has asked. I've come up with an
    >answer, but am curious how others might solve the problem. One person
    >approached it from a completely different direction than I used but
    >got the same answer.
    >paulhirose@earthlink.net (Paul Hirose)

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