> At 7:24 PM -0600 11/3/10, William Robertson wrote:
>> I agree that the bottom will flex up under the box, but for reasons
>> outlined by others. The pressure exerted on the bottom of the
>> aquarium
>> just below the box is less than the pressure exerted on the aquarium
>> bottom all around it. OK - that's fine by me. This force is dependent upon the surface area of the bottom of the box. Bigger box -> less downward force on the bottom. Except for the edges of the box, right? Those push down the same as the water above would've (less the pressure differential (times A) from the height of the box, I think).
Not because of a buoyant force on the box,
>> because you have removed the mechanism for that force, but because
>> there is "less water" above that part of the bottom of the aquarium.
>> And yes, it will be equal to the weight of the water displaced, but
>> that doesn't mean it's a buoyant force pushing up on the box.Now this "force" - which I think you're arguing is equal to the force discussed above (the microscopic view, I guess) - is dependent on the volume of the box, which doesn't necessarily have any relationship to its bottom surface area. Is there a reason to think that these two POV really are equal?