"Leo Lichtman" wrote in message
...
Peter Reilley wrote: For this purpose, the rope is infinitely thin and
weightless. For extra credit, consider the condition where the rope has
neutral buoyancy.
^^^^^^^^^^^^
A boat floats in the water at a depth at which it displaces its own weight
of water. The shape of the hull does not change this fact. When you tie
the concrete block to the boat, in effect you are making it part of the
boat. When you throw the block and rope into the water, you have, in
effect, changed the shape of the hull, without changing its weight, so the
amount of water displaced does not change. Therefor, the pond level does
not change. Making the rope "weightless" or of neutral buoyancy does not
make any difference. The water level does not change.


I believe that we have a correct answer.

Pete.