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Old September 12th 03, 08:59 PM
Chris OCallaghan
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Kevin,

the problem isn't wholly ballistic. That is, it's not quite the same
as firing projectiles of different mass straight up at the same
initial speed. Remember, your sailplane has drag that varies with
speed. Additional mass reduces total drag at higher speeds. That's why
we carry water ballast when racing. Thus, during your pull up, the
ballasted glider will have less drag than the unballasted one, and
will therefore gain additional altitude. Is it alot? No. But
significant.

On a side note, Galileo never dropped objects off the tower of Pisa.
Though he did some work with inclined planes, he recognized that
friction would skew his results (think of dropping a ping-pong ball
next to a golf ball...), and Catholic dogma didn't leave much room for
fault when it came to heresy. Instead, he created a thought
experiment. He postulated that if heavier objects fall faster, a heavy
object tied by a string to a lighter object and thrown from a tower
should pull the lighter object faster, and the lighter object would
impede the acceleration of the heavier one. However, once tied by a
string, they were a single object of greater mass and should therefore
outpace the individual objects. This demonstrated the fallacy of the
argument for "greater attraction" and saved him the embarrassment of
having to demonstrate a flawed experiment to anti-empiricists.