Gentlefolk - Perhaps it is best to resort to an old fashioned tried but true approach. . . . . looking it up in the dictionary. . . . . . The Oxford Dictionary states the following:
displacement . noun 1 the action or process of displacing. 2 the amount by which a thing is moved from a position. 3 the volume or weight of water displaced by a floating ship, used as a measure of the ship's size. 4 Psychoanalysis the unconscious transfer of an intense emotion from one object to another. Putting aside for the moment whether or not we should be using definition 4 since we all own holes in the water into which we throw money, definition 3 appears the most appropriate. It also establishes that there are two correct answers "volume" and "weight" each of which is independant of the other since they are not the same thing. Nothing weighs a cubic foot, nor does anything fill up a pound. Now that we have explained how an aircraft carrier floats, can we move on to my little phobia, why jetliners that are really nothing more than the equivalent of huge bricks don't fall out of the sky, but instead fly. . . . . . George ----- Original Message ----- From: [EMAIL PROTECTED] To: [email protected] Sent: Thursday, August 14, 2008 8:54 AM Subject: RE: catalina27-talk: Hull speed It looks like people are getting displacement, density and bouyancy mixed up. Any object that has a total density less than water will be bouyant and will float. The weight of the water displaced by the object will equal the weight of the object. Objects that are more dense than water will not float and will not displace as much water as their weight. Looking at it from another direction, if you take a cubic foot of water and a cubic foot of another object (lets say a piece of wood) and weigh each, any object with the same volume that weighs less than the water will float. The hull of our boats create a very large volume (mostly filled with very light air and other things that are less dense than water) compared to the total weight of the boat, so the density is much less than water, and our boats float instead of sink. Fair winds -------------- Original message -------------- From: "Joe McCary" <[EMAIL PROTECTED]> I don't think that is how the displacement measurement works. My understanding is all floating or non floating bodies have displacement. When those bodies are placed in or on the water a certain amount of water is displaced. Example, fill a bucket to the absolute brim and float a piece of wood in the bucket; some of the water spills over the rim of the bucket. The water that over flows is equal to the displacement of the wood now floating. The same is true if the object is a toothpick or an aircraft carrier; the water pushed away by the placement of the object in or on the water is the displacement. The steel aircraft carrier floats because it's hull is deeper that it's displacement. Joe McCary Aeolus II, West River, MD [EMAIL PROTECTED] Behalf Of Jim Bernstorf I understand the definition of displacement. The logic of that though is that if the 6000lb boat displaces 6000 lbs of water then it theoretically would be sitting with the water at the gunnels of the boat and adding another pound would push the boat under water and sink it
