# Questions tagged [precession]

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### Rotational Work-Energy Theorem and uniform precession of a gyroscope

For a gyroscope in uniform precession, what would happen if we suddenly turn off gravity? Will it stop precessing because there is no torque and so there is nothing causing the direction of the ...
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### Rolling wheel precession

I wanted to write the equations of the motion of a tilted spinning wheel. I am aware of the effects of precession on spinning things, and I know the equations for the case where the pivot point of the ...
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### Feynman Lectures: 20–3 The gyroscope

In the The Feynman Lectures on Physics, Volume I, Chapter 20, Section 3,The Gyroscope found here, Feynman wrote We note that when the wheel is precessing, the particles that are going around the ...
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### Which way does a symmetric top precess and why?

I'm calculating the (instantaneous) rate of precession of a symmetric top (i.e. $I_1=I_2\neq I_3$) that is tilted at angle $\theta$ to the vertical if a torque $\vec{G}$ is applied, as shown below: ...
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### Do electron have a rotational North/South and magnetic N/S?

Out of curiosity I wonder can an electron have a rotational North/true South which is different from it's magnetic North and magnetic South, if so can we measure the precession?
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### How much force is required to break precession

Gravity, in this diagram, provides a downward force creating a torque that causes the wheel to precess around the chain. This is cool but counter intuitive, and I am wondering what force is needed to ...
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### Does the angular velocity of a wheel affect its height in this situation?

If there were no friction at all, and the wheel was spinning with some angular velocity in the initial picture shown below. Would the wheel stay perpendicular to the ground regardless of the angular ...
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### How can magnetic dipole align if there is precession?

In my lecture notes on paramagnetism and diamagnetism is stated that "according to van vleck critical considering an electron in motion around the nucleus diamagnetic and paramagnetic effect ...
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### Solar frame dragging

Does solar frame dragging induce a higher centrifugal force to Mercury so its orbit is precessing as well as being more outwards than it should be if there wasn't solar frame dragging?
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### Gyroscope precession and Euler equations

I've been trying for so long to solve this problem, but the solution I have found isn't the one I expected. Basically, I have to solve Euler's equations for a gyroscope with a weigth at a distance d. ...
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### Why can a gyroscope go upright for a while, after losing some energy?

There are many questions about gyroscopes, and this one: (Confusion about what happens when the rotating axis of a gyroscope is rotated) remind me of an odd behaviour of a toy gyroscope that I had. ...
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### Proof that for free symmetric top, $\vec{e}$ precess around $\tilde{e}$ at $\Omega$

For free symmetric top $I_1=I_2\neq I_3$, the solution was $\vec\omega(t)= A\sin(\Omega t) \vec e_1 +A\cos(\Omega t)\vec e_2 +\omega^3_0 \vec e_3$ where $\vec \omega(0)=(0,0,\omega_0^3)$ was the ...
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### NMR Bloch equations in 4D?

I'd like to apologize for the purely theoretical question in advance, but I find this an interesting thought-excercise. So basically me and my coworkers asked how the Bloch-equation would look like "...
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Sorry to bother you, but I did not get anywhere answer what exactly moves Mercury periapsis. "Sun gravity" or "GR" or "warp of spacetime" are very broad answers, I want to know how they affect this ...
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### Can we measure the angular momentum of a magnetic domain using precession?

The amount of angular momentum of a single iron atom is small, just $\hbar / 2$. In a single magnetic domain, though, all of the iron atoms have their spins aligned. Presumably, it should be possible ...
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### Nutation angle calculation of spacecraft

I need to calculate the nutation angle of a spacecraft for different timesteps. I have a file which gives me the angular velocity $~w = (w_x,w_y,w_z)~$. When no torque is applied, the inital angular ...
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### Nutation Angle calculation out of attitude Data

I have a rocket body with given Euler Angles, Quaternions and Angular-Velocities for given time steps. And I'd like to calculate the Nutation-Angle for every time step, so that I can plot the cange of ...
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### Manev potencial and some problems with it [closed]

Given the Manev potential by the equation below $$\ V_M(r) = - \frac{-mMG}{r} \left(1 + \frac{\gamma MG}{c^2r}\right)$$ in which: M is the Sun's mass; m is the planet's mass; G is Newton's ...
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### What are the conditions that an asymmetric top will perform precession in space (zero torque)?

The conditions that an asymmetric top will perform precession under gravitational field are described in the article Precession of an Unsymmetrical Top. (I can't get the full article.) But what if ...
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### Balance of a rolling coin

If we place a typical coin on a table, it will almost immediately fall due to gravity. However, with a little push it will roll and not fall anymore until friction eventually slows it down enough to ...
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### Does asymmetric rigid body experience torque-free precession?

I know that a top (or any axis symmetric body) experience torque-free precession. and I know that asymmetric body, with 3 different dimensions has stable rotation when the angular velocity is near the ...
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### Does Larmor precession of a magnetic spin produce a (time-averaged) electrostatic near-field?

I have been wondering whether or not applying a magnetic field to a material containing magnetic spins could produce an electrostatic-like field as a result of a Larmor precession of the embedded ...
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### Dynamics of Gyroscopic P recession

It is taught relatively early in classical mechanics that the precession of a top exists because when the body is spinning, the gravitation torque pushes the rotational axis (more accurately it pushes ...
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### Angular momentum and Gyroscopic precession of a top [closed]

A top is spinning in the counterclockwise direction as seen from above. Its axis of rotation makes an angle of 15º with the vertical. If frictional forces can be neglected, which of the following is ...
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### Nutation frequency for a weighted gyroscope

So, I've been led to believe that the frequency of nutation of a gyroscope can be calculated using the formula In which the I's are the moments of inertia around the principal axes and omega-3 is the ...
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### What is the rate at which a precessing top falls over?

From the following equation from hyperphysics, as rotational speed $\omega$ decreases, precession speed $\omega_p$ increases. However, from what we observe physically, as rotational speed of the top ...
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### Factors effecting the time period of Euler's disk [closed]

I wish to carry out research on the factors effecting the time period of a spinning Euler's disk. Do factors like friction coefficient of the base or concavity of the base effect the disk? If not, ...
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### Anomalous precession of the orbit of Mercury

Can the anomalous precession of the orbit of Mercury be explained just with relativistic length contraction?
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### Angular velocity formula in a precession motion

I find out that in the specific case of a precession motion of a constant in magnitude vector $\vec{A}$ we can say that: $\frac{d\vec{A}}{dt}=\vec{\omega}$x$\vec{A}$. Where $\vec{\omega}$ is the ...
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### Why does an increase in height decrease the spin time of a spinning top?

We know that an increase in height of a spinning top decreases the time it spins for without toppling. Why does this happen? I suspect that this is connected to the fact that an increase in height of ...
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### I have a question about the gravity probe B geodectic precession formula and why it seems to be twice the planetary precession formula

Specifically, I can work out the planetary precession formula to give radians per orbit as 6*pi*GM/c^2r (and I find that on the web at places like http://farside.ph.utexas.edu/teaching/336k/...
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### How to compare the observation with the theoretically predicted result?

On the Wikipedia Article on “Geodesics in general relativity”, it says the following: “Thus, for example, the path of a planet orbiting a star is the projection of a geodesic of the curved 4-D ...
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### Stuck on Weinberg's quick derivation of Thomas precession

In Weinberg's Gravitation and Cosmology he has a pretty concise derivation of the Thomas precession formula (Eq. 5.1.13). But I don't get the first step... A particle with intrinsic spin is under the ...
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### Goldstein central force problem [closed]

I was reading Goldstein chapter 3 central force motion. I tried to do the exercise 21 on p. 130 of 3rd ed. but cant think of any way how to do it. any clue would be very helpful. Show that the ...
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By Newton's gravity equations, 5557 out of 5600 arcsec Mercury perihelion advancement due to other planets gravitational attraction. is it possible that regular asteroids striking forces could explain ...
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### How is a perpendicular angular momentum origin in gyroscopic precession?

Assume in the given diagram, $\theta = 0$, for sake of simplicity Then, I understand there exists an initial angular momentum in the y-direction and a torque in the X direction of the gyroscope. This ...
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### If a gyroscope is provided a torque in space, what will its motion be after the torque ceases to act?

As there will be no energy dissipation, where will the kinetic energy of precession go as the gyroscope can't precess in the absence of a torque? Thanks in advance!
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### What is the difference between precession and spin angles?

I was recently introduced to Euler Angles in a Dynamics course, but I am confused on the difference between precession and spin angles. Both precession and spin consist in rotating a coordinate system ...
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### Start of gyroscopic precession

Let's consider the classical example, the wheel hung by one side of the axle: ¹ When the wheel is not spinning, it will tilt down the free end of the axle first. When the wheel is spinning, it will ...
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### Gyroscopic precession - Angular momentum in vertical direction

In the classic example of gyroscopic precession, the wheel starts to process, and now acquires a angular moment also in the vertical direction. Initial angular momentum was in a single plane. The one ...
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### Planar Precession Frequency of Orbit

What is the general relation between orbital precession $\Phi$, orbital frequency $\Omega$ and a radial perturbation frequency $\omega$? For certain cases the answer is "clear", for example: 1) If \$\...
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I want to analyze the following system, where the mass of the axle is negligible and the Wheel is spinning. In particular I need to calculate the amount of torque about the point where the string ...
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### How do I calculate the energy density of a flywheel rotating along dual axes?

It seems to me that if you can rotate a flywheel along more than one axis simultaneously you can significantly add to the amount energy it can store. So a flywheel that is spinning and precessing(?) ...
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### micron sanding apparatus [closed]

I am in need to shave a special material (composite much like fiberglass/kevlar) from 30 microns down to 10 microns, on a consistent basis. How would I make something like this? or is there anything ...
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### Can precession happen with no external forces?

I wanted to ask the following question: Can a body that experiences no forces whatsoever precess? Let's say I have a body in space - no gravity or anything - can I make it precess without applying ...
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### Why do nuclei precess in magnetic fields?

I understand that a classical bar magnet will precess about the axis of an external magnetic field. Whilst researching NMR, I have read that nuclei with half-integer spin which are subject to an ...
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### Where did Paul Gerber go wrong in arriving at the same equation as Einstein in explaining the Mercury anomaly?

We know that Einstein admitted that Paul Gerber's 1898 formula explaining the anomaly of Mercury's perihelion was the same as his own. Reportedly Gerber had made a mistake somewhere, so - even though ...
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### Can/Does angular momentum apply a torque?

Context I'm a psychologist and I'm interested in perception of gyroscopic forces. For that reason, I'm having to think about many of the classic issues relating to gyroscopes in reverse. That is, ...