Is it possible to pump a swing 360 degrees?

AI Thread Summary
It is possible to pump a swing to achieve a complete 360-degree rotation, especially when the swing is connected by a rigid rod instead of a rope or chain. The ability to manipulate rotational inertia by adjusting body position, such as standing or crouching, plays a crucial role in this process. Performers in circuses have demonstrated this technique using shorter swings, which contribute to a smaller moment of inertia. The discussion highlights the importance of angular momentum in achieving the full rotation. Overall, with the right conditions and techniques, completing a full swing rotation is feasible.
rlaworms
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Is it possible to "pump" a swing 360 degrees?

Homework Statement


Is it possible to "pump" a swing so that it turns in a complete circle? Assume if you wish that the seat of the swing is connected to its support by rigid rod rather than a rope or chain.

Homework Equations


Angular momentum
Li=Lf

The Attempt at a Solution


We know that we can decrease or increase the rotational inertia by standing or crouching on the swing, respectively. However, we are not completely sure if those inertias alone will make it possible to swing in a complete circle.
 
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rlaworms said:

Homework Statement


Is it possible to "pump" a swing so that it turns in a complete circle? Assume if you wish that the seat of the swing is connected to its support by rigid rod rather than a rope or chain.

Homework Equations


Angular momentum
Li=Lf

The Attempt at a Solution


We know that we can decrease or increase the rotational inertia by standing or crouching on the swing, respectively. However, we are not completely sure if those inertias alone will make it possible to swing in a complete circle.

I have seen performers at a "humans only" circus [like cirque du soleil] do it!

Edit: They were using a reasonably "short" swing, much shorter than you see in a children's park, and did it in the standing position, so will have been working with a reasonably small moment of interia? and yes, rods not chains.
 


Oh, thanks. I kind of understand the question now.

So, it is possible to swing 360 degrees...
 
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TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...

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