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Name: Unknown
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Date: Around 1993


Question:
If a block of wood floats in a pail of water with weight sitting on top of it, the waterline say is at the halfway point of the wood block. If we hand the weight from below the block -- into the water, will the water level on the block stay the same, increase, or go down.



Replies:
You are correct that the water displaced should remain the same, and therefore the water level on the block should go down. (since the weight is displacing a little bit of water itself). This should be easy to test though - how about doing the experiment to check it?

A. Smith


If you hang the weight below the block, the water level will no longer reach exactly halfway up the block, but will reach slightly less than halfway up depending on the density of the weight. It is correct to say that the weight supported by the buoyant force is the same whether the weight is on top, or below, the block. Also, the water displaced is the same in both cases. The difference is that the weight displaces water when it is hung under the block, but not when it is placed on top.

Mooney



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