Centripetal forces on a drifting Hangglider?

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    Centripetal Forces
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Discussion Overview

The discussion revolves around the concept of centripetal forces experienced by a hang glider in motion, particularly in relation to wind direction detection without visual references. Participants explore the implications of circling in air that is moving relative to the ground and the associated forces acting on the glider.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants suggest that while circling, a pilot might feel different forces when turning into the wind versus downwind, but this notion is challenged by others who argue that centripetal forces remain the same regardless of whether the object is stationary or in motion.
  • A participant expresses frustration over the lack of responses from experts, implying that the topic may be perceived as too simple for expert engagement.
  • One participant emphasizes that an airplane's airspeed indicator measures relative wind, not ground speed, highlighting the distinction between the two and its relevance to the discussion.
  • Another participant asserts that without visual references, a pilot's ability to detect accelerations is severely limited, suggesting that reliance on bodily sensations in such conditions is dangerous.
  • There is mention of a common misconception regarding the "downwind" turn in radio control gliders, indicating that similar misunderstandings may exist in the hang gliding community.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between centripetal forces and motion, with some agreeing that the forces remain constant while others believe that the perception of forces may vary based on wind direction. The discussion remains unresolved, with no consensus reached on the underlying principles.

Contextual Notes

Limitations include the lack of mathematical proof to support claims about centripetal forces in motion, as well as the dependency on definitions of ground speed versus airspeed. The discussion also highlights the challenges of understanding these concepts without visual references.

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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