>- -----------------------!!! NERD ATTACK !!!----------------------------
>
>> Terminal velocity is the speed at which the drag of falling through
>> the air exactly balances the force of gravity pulling you down.
>
>The resistance of air to the motion of bodies in free fall depends on
>a lot of different stuff - for example: the size of the body, its
>shape, its density, the temperature of the air, the density of the
>atmosphere with respect to height, the velocity of the body through
>the resisting medium...
>
>Lots of variables...I'd worry about them only if I had the leisure to
>set up the numerical analysis. Here's a useful approximation instead -
Well, yes, but what I said was correct...Vt _is_ the speed at which drag
balances gravity.
>- -----------------------------------------------------------------
>> Possibly, GDW considers grav belts to put out a constant force,
>> therefore, they would produce constant speed at max output, like
>> terminal velocity.
>
>I think it is possible, perhaps, that you have confused velocity and
>force?
I rarely confuse velocity and force 8+)
> The force that a grav belt would put out would have to be
>variable. Otherwise, there would be no control on velocity! Recall
Too true.
>that force is (mass x acceleration). If the force is always constant,
>then there would always be constant acceleration and ever increasing
>speed (assuming, of course, that the grav belt force exceeds g...). I
>think you must have misstated yourself :-) because to achieve a
True, I did make a mistatement there. It should have been a variable force,
but with some arbitrary maximum (whether physics imposed or manufacturer
imposed). I think of it like a car...if you depress the gas pedal half way,
you will accelerate to the point where the new forces of friction and drag
balances the new _x_ output of the engine (where x is power, work, force or
whatever is appropriate, I'm kind of fuzzy on that, it's been about seven years
since my last physics course dealing with those concepts).
>I myself have always ignored the limitations on grav belts - what sane
>person would want to go that lethally fast anyway? ;-) (This from a
>woman who's been riding motorcycles for 10 years...) If you can have
>;-) On the other hand, there's nothing that says there aren't either
>speed limits (*gasp* no, not SPEED LIMTS!!!) or speed governers in the
>grav belts themselves.
Probably either speed governors or powerplants small enough such that you
_can't_ go faster than about 300KPH....?
>Catie "Just Another Armchair-Physicist" Helm
>
Paul "Just another kitchenchair-Physicist" Baughman