18 questions linked to/from Is there a way for an astronaut to rotate?
1 vote
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### How can astronauts rotate their body in empty space ? How do they undergo "angular displacement" without any external torque? [duplicate]

How does the astronaut in the following video do what he is doing ? https://youtu.be/7ZPVg3qD07g?t=145 This question is kind of a follow up to Why don't we ever see astronauts on space walks ...
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1 vote
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### Can an astronaut in free space turn his head without moving the rest of his body in opposite direction? [duplicate]

Can an astronaut in free space turn his head without moving (turning) the rest of his body (and also not moving hands or legs) in opposite direction?
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### Is it possible to walk in a friction-less world?

Is it possible to walk in a frictionless world. I think you won't be able to walk because walking depends on friction acting on your feet. I think about it like an ice rink because when you try to ...
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### Intuition as to why the orientation (of a 3D object) is not a conserved quantity?

Say you start off floating in space, in a fixed position and orientation, with zero linear and angular velocity, with no external forces. So you are a closed mechanical system. By twisting your body ...
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### What is a rocket engine thrusting against in space?

I know Newton's third law of motion might be the answer for this but still I am wondering how the rockets could thrust in the empty space and move in the opposite direction. I guess an astronaut ...
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### Changing Rotation Direction in Mid Air

Not sure whether this is an appropriate question for this site, but could anyone explain the physics behind how this skier is able to change his direction of rotation mid-air? https://www.youtube.com/...
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### What happens to our force when we walk on ice?

I'm scratching my head a lot in trying to understand friction. So far I understand that "without friction we would not be able to walk". But that sounds really vague and unclear, so much in ...
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### Cat righting reflex: Is the cat's angular speed zero or non-zero? (Or is it more complicated?)

The cat righting reflex (Wikipedia article) allows a cat to change its orientation in the absence of initial angular momentum or external forces. A theoretical model would work like this: the cat ...
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### What happens to photons after they hit objects?

If I am not wrong when light hits for example white wall most of the photons are absorbed and transformed into heat and few of the photons at certain wavelength are reflected from the object. So white ...
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### Would a sneeze by a cosmonaut in a spacesuit affect his movement?

Naive question; feel free to shoot me down It is a truism that any motion in space would continue indefinitely unless it is opposed by an external force. If a cosmonaut were to sneeze within his/her ...
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### Effect of the tail of the cat in the falling cat problem

To explain why a falling cat can turn by 180 degree without external torque and without violation of the conservation of angular momentum, one usually models the cat as two cylinders as in http://en....
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### When falling through the air, does swinging arms/legs actually help anything?

Let's say someone jumps off an Olympic-sized diving board into a pool below (so air resistance is negligible). As soon as they jump, they start swinging their arms. Does this help them stay upright ...
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### Is it possible to rotate an angle on perfectly smooth ice?

You must start and end with the same pose. Prove it if you think you can't.
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