Questions tagged [rotational-dynamics]
A tag for questions about the mechanical interactions of rotating objects, including torque and angular momentum.
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Why are infinitesimal rotations commutative, whereas finite rotations are not?
Infinitesimal rotations commute and every finite rotation is the composition of infinitesimal rotations which should logically mean they also commute; but they don't. Why?
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What is the proof that a force applied on a rigid body will cause it to rotate around its center of mass?
Say I have a rigid body in space. I've read that if I during some short time interval apply a force on the body at some point which is not in line with the center of mass, it would start rotating ...
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Without saying "cross product" explain why there is a skew-symmetric angular momentum tensor
In Space-Time-Matter Hermann Weyl claims that had we lived in a world of more than three spacial dimensions, we would have known all along that quantities such as angular momentum are skew-symmetric ...
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How can friction do no work in case of pure rolling?
I have read various answers, on PSE and elsewhere, and most of them explain that the point of contact of the rolling object undergoes no instantaneous displacement in the direction of friction, I ...
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Why do non-rigid bodies try to increase their moment of inertia?
I have oft noticed that a non-rigid body on being rotated tries to increase its moment of inertia.
Is there any way we can prove this in a logical and mathematical fashion?
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What determines the direction of precession of a gyroscope?
I understand how torque mathematically causes a change to the direction of angular momentum, thus precessing the gyroscope.
However, the direction, either clockwise or counterclockwise, of this ...
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Why does an unhinged body rotate about its centre of mass?
If a force is applied to a body which does not act through its centre of mass, it rotates about its centre of mass and not any other point. Why?
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What is the electric field generated by a spinning magnet?
Consider a cylinder of permanently magnetized material, with uniform magnetization pointing along the cylindrical symmetry axis (the $z$-direction). The magnet is rotating about its cylindrical ...
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Derivation of Newton-Euler equations
I am in search of a simplified version of the derivation of Newton-Euler equations (both translational and rotational) for a rigid body (3D block) that has a body fixed frame and where the center of ...
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How can the centripetal force lead to objects flying apart?
I don't understand how the centripetal force, which always points to the center of our circular motion can cause this scenario:
We have a big stone which spins very fast, so fast that a part breaks ...
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In car driving, why does wheel slipping cause loss of control?
When driving a car on ice, there is a danger of slipping, thereby losing control of the car.
I understand that slipping means that as the wheels rotate, their circumference covers a total distance ...
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Will a pure rolling cylinder stop on a rough surface? [closed]
Will a disc or cylinder (rigid body) executing pure rolling on a rough surface stop, neglecting air drag and other heat losses and rolling friction but not static and kinetic friction? If yes, due to ...
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Where does "excess" energy go when a vehicle uses a lower gear to move at a given speed?
So I understand that a lower gear as advantageous when accelerating a vehicle or when driving up hill (e.g because you are having to accelerate against gravity). I know this is because of the ...
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Why is it possible to keep an object, say a book, horizontal while holding its corner?
When holding a book from its corner with two fingers in a pinched position, the fingers act as a sort of hinge, and the book is free to rotate about this corner only. The external forces acting on the ...
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Is angular momentum just a convenience?
I'm wondering whether angular momentum is just a convenience that I could hypothetically solve any mechanics problems without ever using the concept of angular momentum.
I came up with this question ...
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