# Questions tagged [classical-mechanics]

Classical mechanics discusses the behaviour of macroscopic bodies under the influence of forces (without necessarily specifying the origin of these forces). If it's possible, USE MORE SPECIFIC TAGS like [newtonian-mechanics], [lagrangian-formalism], and [hamiltonian-formalism].

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### Understanding the phrase "Classical mechanics corresponds to the high frequency limit of quantum mechanics"

Recently I have taken an interest in mathematical physics and as my background is mostly in math itself, I have quite a lot of catching up to do regarding my knowledge of physics. One phrase that I ...
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### Phases of vectors

This maybe because I am missing a whole concept itself, but how can vectors have a phase? I have been studying forced oscillations and I read that when multiplying a vector with i (sqrt(-1)) , the ...
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### Rayleigh's Dissipative Function in Lagrangian Mechanics

What exactly is the derivation of Rayleigh's dissipative function? How does one know what to assume the function to be while dealing with a problem in Lagrangian mechanics? These two questions have ...
1 vote
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### Independence and ambiguity of holonomic constraints

I've got a couple of questions concerning constraint equations: Suppose I've got $n$ holonomic constraint equations for a particle, how can I be sure those are all the ones there are and I didn't ...
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### Does the direction of angular momentum of a table fan different for two people standing behind the fan and in front of the fan?

Does angular momentum of a table fan depend on place of observation? What is its direction of angular momentum of a fan when I stand behind a table fan? In front of a table fan? And along the same ...
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### What's a good simple model for wind attacking drone?

I'm trying to simulate a drone on https://rapier.rs/. My idea is to do an X shaped object, with a force $P$ on each end of the X, always perpendicular to the drone plane. I want to simulate wind, ...
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### Is there a difference between a pattern's results and its processes? [closed]

Is there a difference between a pattern's results and its processes? The following link will send you to Wikipedia site where they define Pattern
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### Why do we apply a Legendre transform to the Lagrangian in the first place? [duplicate]

I understand how the legendre transform of the Lagrangian with respect to $\dot{q}$ yields the hamiltonian, but I do not understand why one would think to do this in the first place? what is the ...
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### Why is the action guranteed to have unique extrema in classical mechanics? [duplicate]

Reading any classical mechanics book which introduces the Lagrangian formalism of mechanics, a one particle system is introduced to show that we obtain the euler-lagrange equations from Newton's ...
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### Why is the action guranteed to have one unique extrema in classical mechanics? [duplicate]

Reading any classical mechanics book which introduces the Lagrangian formalism of mechanics, a one particle system is introduced to show that we obtain the euler-lagrange equations from Newton's ...
1 vote
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### Equations of motion of a car with variable mass and drag [closed]

Lately, I've been trying many ways to attain these equations, yet I've not succeeded in any. I'm basically using Newtonian mechanics because it's the most suitable for this case with dissipative ...
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### Multiplying non-constant acceleration by a constant on every point - would the total path be multiplied by the same constant?

If the non-constant acceleration is multiplied by a constant (on every point), would the total path also be multiplied by the same constant over the same time? Both starting and ending speeds are zero ...
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### Do all objects in a system need to have the same acceleration? [closed]

What is the definition of a system? Could multiple objects accelerating at different magnitudes and directions still be considered a system?
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### Why flapping rudder produce net thrust if one half-stroke produce thrust and second half-stroke drag?

In small sailing boat like optimist is well know technique when there is no wind, rudder pupming which push boat forward.You just need push-pull rudder stick left to right with fast movement. Rudder ...
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### What are some examples of microscopic quantities?

Mass, volume, energy, entropy, temperature, pressure are some macroscopic quantities. Which means we can think of them even without considering the molecular nature of matter. What are some examples ...
1 vote
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### Does the force that need to be applied to pull the weight out of a well by string is more at the start?

One way to estimate depth of the well is attaching a weight to a string then throwing it into the well until it touch a hard surface then pulling the string out of the well and evaluate its length. ...
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### Yet another perpetual motion machine: does this imply large selective membranes are not possible? [closed]

So I was just thinking about the buoyant force and came up with what seemed like a simple perpetual motion based on it. Obviously such things are not physically possible so I'm trying to figure out ...
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### Necessary torque calculation for rotating a heavy object?

I'm trying to create something like the image below, where a motor will be connected to a gate/big piece of wood, which will be hinged so that the motor can rotate the gate. I know the weight (4lbs) ...
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### Why classical mechanics is not able to explain the net magnetization in ferromagnets?

Why classical mechanics is not able to explain the net magnetization in ferromagnets? why does exchange interaction can explain net magnetization in Ferromagnets, which is purely quantum mechanics??
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### Stress and equilibrium

By newton's third law, all internal forces in a portion of volume must be zero. Thus the total force is due to other volume portions exerting force onto the surface of said portion. However, if one ...
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### Where does the excess energy go in this problem?

Two identical plastelin balls were suspended on a non-extensible weightless string with the same length L, which are fixed at the same point. One of the balls was deflected 90 degrees from the ...
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### Do Legendre transformation form a group?

In my classical mechanics class, my professor asked if Legendre transformations form a group, and in my little knowledge about groups, I know that a transformation group consists of a set of ...
1 vote