Classical mechanics refers to the classical (i.e., non-relativistic, non-quantum) study of physics. Three major formulations of classical mechanics are newtonian mechanics, lagrangian mechanics, and hamiltonian mechanics. The latter two are rather useful in extensions to Classical Mechanics; ...

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What forces are at work in a loose ball bearing bicycle hub?

I've landed in a physics debate amongst bike mechanics. In a typical bicycle hub you have a simple bearing; the cups are set in the hub, the race (cone) threads onto the axel and there are just loose ...
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4answers
445 views

Does screwdriver length matter?

Everyone who deals with screws and screwdrivers knows that long screwdrivers are stronger than short ones. However, I can't find any relationship between length of a screwdriver and mechanical ...
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0answers
32 views

How to find the Kinetic energy of a quarter of a wheel? [on hold]

A wheel of mass 'm' and radius 'R' is rolling on a level road at a linear speed 'V'. What is the kinetic energy of the upper right quarter part of the wheel , considering the wheel to be of the ...
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2answers
28 views

Derivation of ensemble distribution

I heard that you can derive the canonical ensemble by maximizing $L = \sum_i p_ilog( p_i ) + \alpha (\sum_i p_iE_i-E)$ or for the grand-canonical ensemble $L = \sum_i p_ilog( p_i ) + \alpha ...
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46 views

Good introduction to classical mechanics with math [duplicate]

Right now, I'm reading "Classical Mechanics" by Kibble and Berkshire. Already in chapter 2, I have found a concept being discussed that assumes you have prior knowledge. Specifically, it describes the ...
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2answers
20 views

Understanding a graph of energy conservation with bounded and unbounded motions?

This graph is from the physics undergraduate text "Classical Mechanics by Douglas Gregory". Above this graph was the statement: What I didn't understand is- as stated in the under [*paragraph], ...
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1answer
47 views

Energy in harmonic oscillator [on hold]

The expectation value of the potential energy is exactly half the total according to Griffiths. Is that case always true for quantum harmonic oscillator? Is that the case also for classical harmonic ...
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0answers
16 views

Isolate an electronic drum from the ground

Please note that I know nothing about this part of physics, so sorry if I make some mistakes. Drum is an awesome instrument, yet it can easily make your neighbours very angry.The vibrations caused by ...
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1answer
12 views

What is difference between anisotropy and inhomogeinity of this type of composite material?

I am studying some types of composite materials having 2 phases - fibers and matrix. I have some questions and confusions. Any help is appreciated. The composite has fiber along length and I am ...
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0answers
23 views

Translational acceleration of cylinders [closed]

Two cylinders with total mass $M$ and radius $R$ are connected by a massless rod along their axis of rotation and rest on a horizontal surface. A frictionsless ring at the center of the rod is ...
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1answer
72 views

Work-Energy theorem vs conservation of mechanical energy? [closed]

Bodies A and B are moving in the same direction in a straight line with constant velocities on a frictionless surface. the mass and the velocity of A are: 2kg and 10m/s. The mass and the velocity ...
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47 views

Theory books for physics upto Irodov level [duplicate]

Problems in Physics by IE Irodov is a very popular book amongst students for problem solving. It has very good problems. However, most of the popular high-school physics textbooks like Resnick ...
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1answer
45 views

Coupled ODEs that model a quad rotor

I am working on modeling the vibrations of a quad rotor. The arms that support the rotors are fixed to a center plate; that is, it is pretty much a cantilever beam with an end load. Since this is the ...
2
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1answer
73 views

Lagrangian and Hamiltonian EOM with dissipative force

I am trying to write the Lagrangian and Hamiltonian for the forced Harmonic oscillator before quantizing it to get to the quantum picture. For EOM $$m\ddot{q}+\beta\dot{q}+kq=f(t),$$ I write the ...
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0answers
9 views

Pivotal door - how is the load distributed?

A pivotal door, where instead of the door hung or cantilevered from the hinges screwed to the frame, the door is hung using a top and bottom pivot. The bottom pivot assembly's the floor-spring is ...
1
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1answer
38 views

Rotational Mechanics: Conservation of Angular Momentum

Consider a case where a person stands on top of a rotating disk. The disc is given to rotate at a constant rate. There are two possible movements of the man: He moves away from the center: In this ...
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0answers
22 views

Kinetic energy of the spring

Suppose we have spring of mass $m$ initially at rest , now instantaneous velocity of $v$ is given at both ends in opposite direction (nothing is attached to spring) so what will be kinetic energy of ...
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1answer
39 views

Pressure in Harmonic Oscillation

Classical Harmonic oscillator's energy depends on temperature as it equals $k_B$$T/2$. However, quantum harmonic oscillator energy is $(n+1/2)hf$. So, when T=0, quantum predicts motion. I have been ...
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0answers
47 views

Interpretation of partition function and thermodynamic potential

So in the microcanonical ensemble the partition function $\Omega$ counts the number of microstates for a given $(NVE)$ configuaration and $S = k_B \ln (\Omega)$ is the entropy. The most likely state ...
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2answers
61 views

Problem in Euler-Lagrange imply Newton

I'm self-studying Mechanics and I have a little problem: We can see that in Landau's book or in Wikipedia that when we inject the lagrangian in Euler Lagrange equation the term $\frac{\partial ...
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1answer
44 views

Koopman Von Neumann state vs Quantum state

Is it correct to think that a state in Hilbert space represents the "most we can know" about a system? Is therefore a state in KvN Hilbert space the same as a state in the usual quantum Hilbert space, ...
2
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1answer
39 views

Everyone calls Electromagnetic Induced Transparencyan interference phenomenon, but is it also an interference phenomenon in classical systems?

Electromagnetically induced transparency is a hot topic in physics. However I'm curious about its mechanics in physics. Physicists think that it's a phenomenon of interference from transition of two ...
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2answers
36 views

Angular Velocity

I have the following question regarding an ideal rigid body. Firstly, is it always true without any exceptions that the angular velocity of any point about any other point on a rigid body is always ...
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15 views

Need mechanics problems with solutions [duplicate]

Help me to find the best book for mechanics problems with solutions
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27 views

Classical mechanics textbook recommendation [duplicate]

I've just finished my first year of physics study and I'd like to learn some more classical mechanics. What textbook would you recommend as an introduction to Lagrangian and Hamiltonian mechanics? ...
2
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0answers
31 views

Force and Energy in robots

There are two similar and hypothetical robots that move with wheels powered by motors, Robot A and Robot B. Robot A has a gear ratio of 3:1 (The gear connected to the motor is three times larger than ...
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1answer
28 views

De Donder Weyl theory

Im trying to get my head around what the difference is between a symplectic and multisymplectic manifold is. My understanding currently is that on a symplectic manifold time is the parameter that ...
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1answer
36 views

determining phase constants in SHM [closed]

A particle moves along the x axis. It is initially at the position $x$ of $0.300 m$, moving with velocity $v$ of $0.070 m/s$ and acceleration $a$ of $-0.330 m/s^2$. Suppose it moves with constant ...
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0answers
44 views

Partition function microcanonical ensemble

I was wondering if there is a way to understand the partition function for a microcanonical ensemble $$\mathcal Z(E)=\sum_{\text{microstate $i$ with energy $E$}} w_i$$ as a limit of the continuous ...
3
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2answers
134 views

The force of gravity is $F_g=+mg$ or $F_g=-mg$?

I have noticed that in my classical mechanics course and in the textbook I read for it, seem to ignore the gravitational force's position. For example, if we were dealing with a system with a ball of ...
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0answers
20 views

Energy of a stationary wave on an infinite string

as an optimisation problem, one is given an infinite string on which a stationary wave is present, nodes being placed at period P. One also is given a function E(P) characterising how much energy per ...
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1answer
42 views

Questions about basic jump physics

This is a problem a friend and I are working on for an undergrad reading course. Our goal at the end is to make an accurate two-dimensional model of the human jump using Processing by the end of next ...
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1answer
53 views

Gravitational work

As far as I know gravitational work is independent from the path of the object, and I have an object that goes up on a inclined plane to a certain height, and than, after the object reaches the edge ...
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0answers
45 views

Reduced phase space density

I have a dimensional problem with the single particle phase space density The partition function in the microcanonical ensemble is of course dimensionless Thus $$ \rho ( q, p ) = ...
4
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0answers
67 views

References to Mechanics (Classical, Quantum, Statistical) using Time-Scale calculus?

Time-Scale Calculus, is a theory which unifies ordinary (plus fractional and q-) calculus with discrete (and finite differences) calculus. In a sense, in a similar way the Lebesgue integral (or ...
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0answers
31 views

Interchanging of variation and integration operator for holonomic systems

Meirovitch says in his "Principles and Techniques of Vibrations" (1997) on p.85: In the case of holonomic systems, the variation and integration processes are interchangeable (...) which means ...
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1answer
116 views

Ideal gas in ensemble

I want to calculate the phase space density for a single ideal gas particle in a microcanonical ensemble. I know that the partition function is given by the well-known expression that you find for ...
4
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2answers
61 views

Partition function containing QM?

I am wondering about the partition function of the classical microcanonical ensemble. It contains Planck's constant and also an indistinguishability argument about the particles I am looking at and I ...
1
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3answers
43 views

Why do we add the spin angular velocity and orbital anglar velocity when asked to calculate total angular velocity of Gyroscope?

Normally when we talk of angular velocity we mean how the angle of a vector changes with time with respect to an origin.Thus the oribital angular velocity of gyroscope makes sense to me.However I find ...
2
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1answer
47 views

momentum and energy of the rods

I have two electromagnets and I attach them to two rods(same mass) such that, first one will be attached to centre of first rod and the second one will be to the end of second rod. Now I bring them ...
1
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1answer
49 views

Confusion in Euler-Bernoulli beam theory

Euler-Bernoulli beam equation is given by $$ EI \frac{\mathrm d^2 u}{\mathrm d x^2} = M'(x) \\ EI \frac{\mathrm d u}{\mathrm d x} = xM'(x) + C_1 $$ Where, $E$ is modulus, $I$ is second moment of ...
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0answers
46 views

Stress Force - Understanding Cauchy Stress Tensor

I've been trying to understand the derivation for the Cauchy Momentum Equation for so long now, and there is one part that every derivation glides over very quickly with practically no explanation ...
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1answer
74 views

Can the angular momentum of any rigid body (symmetrical or asymmetrical) be found this way?

Can the angular momentum of anybody regardless of whether its symmetrical about the center of mass or not be found by finding the angular momentum about its center of mass and summing it up with the ...
2
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1answer
55 views

Equilibrium in Stat Mech and Phase space density

I was wondering if there is any relationship between equilibrium in Stat Mechanics and the phase space density of a system? This does not seem to be completely independent, as Entropy is maximized in ...
1
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1answer
84 views

Euler-Lagrange equations of a current-loop pendulum in a magnetic field

I am reading "Nonlinear Electromechanics", by Dmitry Skubov and Kamil S. Khodzhaev, Springer 2008. Here is the relevant and freely available chapter. Essentially, a loop of area $S$, mass $m$, moment ...
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2answers
128 views

I need help figuring out what is wrong in this aspiring perpetuum mobile

Credits: My question is motivated from a question from another user (One disk/ring in double rotation and sum of energy), I just reformulated what I think he tried to ask into, what seem to me, ...
1
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1answer
80 views

Langevin equations in translational and rotational direction

I want to describe the following system. A bead is connected with a tether. There is a force $\vec{F}_{up}=F_{up}\hat{y}$ that acts on the bead. The tether acts with a force on the bead, this force ...
6
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1answer
128 views

Understanding Poisson brackets

In quantum mechanics, when two observables commute, it implies that the two can be measured simultaneously without perturbing each other's measurement results. Or in other words, the uncertainty in ...
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0answers
22 views

Trying to model the acceleration of a system due to an impulse forcing function

My team and I are working on a design project to design/modify a device that can go on hikes for paraplegic/quadriplegic people. Here is the current design (not designed by us): We are thinking ...
2
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1answer
53 views

Finding the maximum extension of a Spring

I have solved that after the body m1 hits m2, the velocity of m2 is going to be (3/4)*v0. I did this by using the law of conservation of momentum and using the coefficient of restitution (relative ...