Centripetal forces on a drifting Hangglider?

AI Thread Summary
The discussion centers on understanding how to determine wind direction while hang gliding without visual references. Participants debate whether a pilot can feel changes in ground speed during a turn, suggesting that centripetal forces remain constant regardless of the glider's movement. Most agree that ground speed is irrelevant, as aircraft operate relative to the air, not the ground. The conversation emphasizes that without visual cues, pilots cannot accurately gauge wind direction or speed. The need for mathematical proof to support these claims is highlighted, but some argue that the concept should be intuitively understood.
GlenK
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entripetal forces on a moving axis of rotation

OK Guys, we need some help to finish a debate over on our Hanggliding forum.
A question was raised, is there anyway of telling wind direction with NO visual reference (cant see the ground etc)
http://www.hanggliding.org/viewtopic.php?t=5451&postdays=0&postorder=asc&start=100
It was suggested that while circling you would be able to feel more force turning upwind to down wind ( I was guilty of believing this for a second)
Say you were circling in air that was moving over ground at the flying speed of the glider your in. At the point in the circle that you were facing headwind you would have a ground speed of 0 then as you continue the circle your ground speed would accelerate from 0 to double the gliders speed on the down wind portion of the circle, then you would decelerate back to 0 ground speed again as you went down wind to up wind.
But most have agreed this is wrong and the centripetal forces on a moving object(spining a weight on a string traveling in a car moving at a constant) is the same as while sitting still.
BUT we need the maths etc to show how a its still the same even while moving.
(assuming it is) PLEEEEEEEEEAZE help!
 
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Sorry guys, I stuffed up the title on my last post, the title doesn't seem to change when i edit it and i don't seem to be able to delete it.. I fear no one will bother looking at it, so ill try again.
OK, we need some help to finish a debate over on our Hanggliding forum.
A question was raised, is there anyway of telling wind direction with NO visual reference (cant see the ground etc)
http://www.hanggliding.org/viewtopic.php?t=5451&postdays=0&postorder=asc&start=100
It was suggested that while circling you would be able to feel more force turning upwind to down wind ( I was guilty of believing this for a second)
Say you were circling in air that was moving over ground at the flying speed of the glider your in. At the point in the circle that you were facing headwind you would have a ground speed of 0 then as you continue the circle your ground speed would accelerate from 0 to double the gliders speed on the down wind portion of the circle, then you would decelerate back to 0 ground speed again as you went down wind to up wind.
But most have agreed this is wrong and the centripetal forces on a moving object(spining a weight on a string traveling in a car moving at a constant) is the same as while sitting still.
BUT we need the maths etc to show how a its still the same even while moving.
(assuming it is) PLEEEEEEEEEAZE help!
 
We have a 12 page argument on our forum yet not even 1 response from an expert here.
Im sure its probably so simple you can't be bothered, like trying to explain to someone that 2+2=4 , If they don't get it straight away they never will ?
 
No, way! Flying by the seat of your pants in IFR weather WILL get you killed, because your body is very BAD at detecting accelerations with no visual reference to aid it.

Also, an airplane does not know or care about ground speed. An airspeed indicator measures the relative wind to the pitot probe. You could have 100KTS headwind and stand still relative to the ground. The airspeed indicator would show you going 100KTS.
 
GlenK said:
But most have agreed this is wrong and the centripetal forces on a moving object(spining a weight on a string traveling in a car moving at a constant) is the same as while sitting still.
BUT we need the maths etc to show how a its still the same even while moving.
(assuming it is) PLEEEEEEEEEAZE help!

You won't need math to prove it. Ask them how the glider (or the pilot) knows ground speed from Adam. Ground speed is irrelevant.

If they can't see that, no math is going to convince them.
 
Aircraft fly relative to the air, not the ground, without the equivalent of a GPS system, there'd be no way to know the speed of the wind relative to the ground. For radio control gliders, there's a similar myth about the "downwind" turn.
 
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