226: Swingset

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Swingset
Someone bring me a pocket fan so I can drift around the yard.
Title text: Someone bring me a pocket fan so I can drift around the yard.

[edit] Explanation

In the opening panel of this comic an unknown woman sees Cueball sitting on a swing set. She tells him that during his swing he becomes weightless. Cueball then imagines that at the peak of his swing he is able to become permanently weightless, floating above the ground without any support.

When on a swing or other pendulum ride, there is a moment between swinging forwards/backwards and swinging back down again when, the forces of gravity, friction, air resistance, etc., brings the velocity of the swing to zero. At this moment, there is no acceleration toward the pivot of the swing (since the centripetal acceleration is proportional to the square of the speed). So the swinger experiences no centrifugal force. Of course gravity still acts on the person, but if the swing is horizontal at that point, then the there is no reaction force, so for one moment the swinger is in free-fall and experiences weightlessness. On a real swing,

In the title text Cueball asks for a pocket fan, believing he could fly around the garden using this small device perhaps as a propeller.

[edit] Transcript

[Woman talking to Cueball on swing-set.]
Woman: You know, at the peak of a big swing, you become weightless.
[Thought bubble from Cueball.]
[Cueball swings higher and higher. At the peak of a big swing he shoves off the swing. Cueball remains hovering in the air.]
Cueball: Hey guys. Come check this out.
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Discussion

A glass with water can be momentarily inverted at this moment and the water will not leave the glass!--DrMath 08:56, 16 November 2013 (UTC)


Isn't the point about illustrating that you do in fact have weight even in instences that are written off as weightless? In space you just happen to be falling at the same velocity of your surroundings, maintaining orbit simply by moving fast enough to miss the Earth. On top of which, in a low enough orbit g is still close to 9.8 m/s^2 if only because altitude is insignificant compared to the radius of the Earth.--Passing Stranger 14:10 August 2014 (UTC)
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