# Tagged Questions

A tag for questions about rotational motion, including angular velocity and angular acceleration.

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### Why do we ignore rotational energy in monatomic gases? [duplicate]

I understand that the average energy of each degree of freedom in a thermodynamic system is $\frac12kT$. And so, for an ideal monatomic gas, there are three degrees of freedom associated with the ...
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### Does gravity play a role in the Earth's equatorial bulge? [duplicate]

I'm trying to understand why the Earth bulges at the equator. But before looking at the Earth, which introduces gravity, I wanted to make sure I understood the shape of some rotating objects and if/...
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### Kinematics of Euler angles relative to a rotating frame

I have a rotating body $B$ and a rotating frame $F$ whose orientations are described by the quaternions $q_B$ and $q_F$ respectively. I also have the angular velocity vectors $\omega_B$ and $\omega_F$....
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### Euler Angles with respect to base body when Euler Angles with respect to another body is known

Let's say I have a fixed base body $B_0$ with a reference frame $X_0Y_0Z_0$, and two other bodies, $B_1$ and $B_2$, rotated arbitrarily with respect to this base body. Coordinate systems fixed to $B_1$...
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### On the no-faster-than-light in special relativity

In the special relativity it is well established that, in the vacuum no one can ever travel faster than light, due to the relativistic velocity addition formula. Recently I saw some silly statement ...
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### Combining moments of Inertia in gear chain

I've got two objects connected by a rod along it's axis of rotation (e.g. a sphere on top of a flat cylinder rotating around it's symmetric axis). Assuming the effects of the rod are negligible, is ...
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### Angular acceleration - radial & tangential

Since ever I knew that radial (angular acceleration) is equal to $W^2 * R = V^2 / R$ and that the tangential depends in the situation (School physics & calculus). Recently I encountered the ...
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### Equation of Motion for Rigid Body Motion

In a paper, eq 24 I am reading, the author mentions the equation of rigid body motion which is written as the sum of translational motion of the centre of mass, $x_G(t)$ and a rotational term about an ...
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### On application of angular momentum conservation laws

Consider a situation like this: a massless ring is kept fixed at rest on a horizontal plane. A massless thin string attached at its one end to a point on the circumference of the ring while its other ...
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### How to calculate a rotating (and constantly decelerating) wheel's angle and speed at a given time in the future? [closed]

So imagine a wheel (a bicycle's wheel) that's spinning slower and slower (because the bike brakes). The time it takes for the wheel to complete one revolution increases in a linear way. Say it starts ...
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### Centripetal acceleration units

I perform some basic calculation for circular motion. Formulas we get from school are: $v$ - Linear speed with the units m/s $r$ - Radius of curve in meters $\omega$ - Angular speed with the units ...
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### Why is the Earth self-rotating? [duplicate]

What drives this happen? Would it be the internal energy or by an external force? I did try to Google the answer, but could not find a good one.
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### How do I transform onto a relativistic rotating frame of reference?

In classical mechanics, the usual formula to translate the evolution of a quantity as seen from an inertial frame of reference to a rotational frame is: \frac{d \textbf{A} }{dt} \vert_{Inertial} = \...
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### Making water spin a wheel [closed]

Let's say that I have a wheel with 8 symmetric arranged rectangular plates of area $A$ and the water, with density $\rho$, in the river it moves with $v\: \mathrm{m/s}$. How do I calculate the ...