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Goofball_star_dot_etal Goofball_star_dot_etal is offline
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First recorded activity by BoatBanter: Jul 2006
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Default Buoyancy is Imaginary

Jeff wrote:
Goofball_star_dot_etal wrote:
Jeff wrote:
KLC Lewis wrote:
Never argue bouyancy with Roger Long. ;-)

Why? I think Roger is making a big deal of a very fine distinction.
Its true that an object that is said to be "buoyant" does not
generate a force by itself, the force really comes from water
pressure which in turn is caused by gravity. But, the force is real
and buoyancy is simply a convenient way to aggregate the net pressure
on an object. If there were no force (regardless of what we call it)
holding up a ship, it would sink.

There are, of course, imaginary forces, such as Coriolis which
appears in non-inertial reference frames, but that is a different thing.


Budding naval architects should teach themselves the rudiments of
dimensional analysis... and then they won't make appalling cockups in
their use of incompatible units.

So who do you think is making an appalling cockup? And in which context?


There are numerous examples of equating inconsistant units. Here is one
example of gobeldygook:

"Note the net downwards displacement of the air. The essence of all
Newtonian physics is the symmetry of energy conservation (the equal and
opposite reaction business). The work done by accelerating the mass of
air downwards is exactly equal to the work required to keep the aircraft
aloft. The work required to shift it from left to right in the
animations is an important aspect of the drag that the engine must
overcome."

http://www.rogerlongboats.com/Circulation.htm