Tagged Questions

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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Why can I put my hand through sand but not a table? [duplicate]

I've read in books that one can't put one's hand through a table because the table offers a "Normal Reaction" to the hand. And it is also stated that this force is electromagnetic in nature. But what ...
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Composing integrals in physics?

OK... so this problem isn't really specific... it's more of a conceptual puzzle. I've recently started using integrals while solving problems in physics (specifically Newtonian Mechanics and other ...
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Alka Seltzer Model: formulas/models requested [closed]

This evening I became fascinated with how my Alka Seltzer tablet disintegrates over time within a small portion of Diet Lipton Citrus Ice Tea. I used a nearly frozen cup; tall, as one might request in ...
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Region of resonance and overlap

In planetary dynamics what does a region of resonance (mean motion) between two bodies mean and how to quantify the region? How does resonance overlap occur and what are its consequences? What is ...
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Earnshaw's theorm and Effective potential

Earnshaw's theorm says "no stable equilibrium for any $\frac{1}{r}$ potential field in charge-free space". Now I am confused in some aspects, and I would like some helping hands. 1.)General physics ...
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What would happen if we tried to run a motor in space when it is not attached to anything to provide support to it?

I know that a when a motor runs it generates torque and that torque can be used to do useful work. On the other hand, the motor needs strong support that absorbs the reaction torque. In our case let ...
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What is the classical counterpart of an eigenstate?

Does this question make sense for every system or just some? If it makes sense, it is a periodic orbit?
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how is this kind of rolling motion possible?

I was solving this problem : Suppose you put a sphere in a rough ground with velocity of center of mass $v_{cm}= v_o$ in the positive $x$ axis and with anticlockwise angular momentum $\omega_o$ so ...
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How to make a body rotate about a line that does not go through its center of mass by applying external torques

In space, is it possible to make a body rotate a point that does not go through its center of mass by applying external torques?
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Particle slides on incline where incline angle increases with rate $\omega$: why does kinetic energy have a term $(1/2)m(\omega^2 x^2)$?

A particle slides on a smooth inclined plane whose inclination is $\theta$ is increasing at a constant rate $w$. If $\theta = 0$, at time t = 0 at which time the particle start from rest, Find the ...
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Making Pudding; A complicated non-equilibrium statistical process?

There are a lot of non-equilibrium processes examples given in physics literature. But some processes that are present in everyday life are not treated. As an example, the formation of pudding can be ...
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If Lagrangian, $\mathscr L = \dot{q}^2 - q \dot{q}$. Then what can be inferred about the particle? Simply that it is a free particle or something else?
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Terminology: Gauge stress?

When a material is loaded with a force, the stress at some location in the material is defined as the applied force per unit of cross-sectional area. If I have a material submerged in pressurized ...
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How to work out the gravitational potential energy of rotating rod

I know that the kinetic energy of a rotating rod is $$KE_{rot}=\frac12I\omega^2$$ where $I$ is the moment of inertia. But is there some way to calculate gravitational potential energy using just ...
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Is rigid body rotation an integrable problem?

Is there chaos? The configuration space is 3d. There are four constraints, namely, the energy, the three components of the angular momentum. So there are still two degrees of freedom.
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Time-independence of Hamiltonian of atomic chain

In the first chapter of Atland and Simons book he gives the Hamiltonian of the atomic chain $$H[\pi,\phi] = \int dx \Bigg(\frac{\pi^2}{2m} + \frac{k_sa^2}{2}(\partial_x\phi)^2\Bigg)$$ After ...
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Can all the theorems of classical mechanics be deduced from Newton's laws?

As above, is the whole edifice of Newtonian mechanics built upon Newton's three laws of motion? Can I deduce all the theorems without referring to further assumptions?
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rotational springs

With a normal spring, you compress it using a linear force to store energy and then it decompresses and releases the energy, again in a form of linear force. Is there a mechanical mechanism that ...
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How does one write Newtons 2nd Law using the language of forms?

Newton's second law says that $F=ma$. Supposing that the force is conservative and can thus be expressed in terms of a potential $V$ we have that $F=-dV$. We have that $V$, being a function, can ...
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Magnetic field on axis of solenoid

So first I'd like to say that I have asked similar questions to this one. However, all the answers involve a level of calculus that I do not yet know. (Still on limits, going to spend the rest of ...
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Will the water go inside the moving water bottle?

Let's say that there is a empty bottle in the water moving at a high speed like this: My question is: Will the water go inside the the empty bottle when the bottle is moving at a high speed? If yes,...
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Pendulum moving faster than speed of light

In classical mechanics, the period $T$ of a pendulum is given by $$T = 2\pi\sqrt{\frac{l}{g}},$$ where $g$ is the gravitational field and $l$ the length of the rope attaching the bob to the pivot. ...
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7/2 versus 9/2 for diatomic heat capacity

Question I calculated the classical heat capacity of a diatomic gas as $C_V = (9/2)Nk_B$, however the accepted value is $C_V = (7/2)Nk_B$. I assumed the classical Hamiltonian of two identical atoms ...
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Why does angular momentum change only its direction and not its value (module) in the case of a spinning top?

I have a doubt, I hope you can help me. In the case of a spinning top precessing around the $y$-axis, there's a torque $\vec \tau$ which comes from the weight of the toy. This torque is perpendicular ...
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Forces and the light

Do external forces can affect the light? Can any external force make the light accelerate? And if it can, will it accumulate mass? (according to the second Newton's law of motion $m = F/a$ ) We know ...
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Newton's laws and the maximum speed

According to Newton's second law of motion : $F = ma$ In an certain occasion, we exert 2 forces (the magnitudes of the forces are the same) on 2 different objects, Object A and Object B, in the same ...
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I do not understand how tightrope walkers return themselves to equilibrium. I am not concerned with the direction along the rope or wire where their base can be large, and they are able to move ...
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Compute distance travelled based on a yaw-rate

Assume that a rigid body is traveling with constant velocity $v$, and (this rigid body) is rotating with a constant yaw rate of $\dot{\theta}$. Find the distance travelled in one time step, $\Delta t$....
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Book about fundamentals and concepts of classical mechanics [duplicate]

I want a book about fundamentals and CONCEPTS of classical mechanics. I have several books about classical mechanics, but all of them go directly to equations and applications. I don't know Really ...
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Beyond the third time derivative [duplicate]

Why do texts on classical mechanics never mention any derivative of position beyond the jerk, while at the same time being general in the sense of using of generalized coordinates?
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Generalised velocities enough to be deterministic in Lagrangian mechanics?

In classical determinism we need to know $2n$ quantities of our system and the equation of motion to predict it's future. In Lagrangian mechanics this is equivalent to knowing $q$ and $\dot q$, the ...
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Why aren't the weights of the beads considered in this equation?

I was solving this problem: A ring of mass $M$ hangs from a thread and two beads of mass $m$ slide on it without friction.The beads are released simultaneously from the top of the ring and slides ...
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Method of calculating eddy currents of a conductor, is this correct?

I have a conductor with volume $V$, passing a magnetic field($B$) with velocity($v$): I'm trying to calculate the Eddy currents to figure out the magnitude of the drag force($F_d$) generated the ...
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Free energy of coupled classical harmonic oscillators

I'm looking to find the thermodynamic (NVT) free energy of a classical coupled harmonic oscillator system such as the one below: (image taken from http://openmetric.org/StatisticalPhysics/...
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With a machete, why is a diagonal cut more effective than a right angle one?

When cutting back some thick growth in the garden a question that always nagged me. Why is cutting diagonally seemingly more effective than cutting at right angles? Part of the answer is obviously to ...
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Kater's pendulum graph

I was told that the graph of position vs period must be a straight line in Kater's pendulum, but my findings are more curved, also after searching in google graphs are like parabolas, my question is ...
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Variable tension in rope connected to mass

Problem 3.9 from Kleppner and Kolenkow's text An Introduction to Mechanics involves a uniform rope of length $L$ and mass $m$ that is connected at one end (its "bottom" end) to a block of mass $M$ and ...
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What is an effective potential in classical mechanics?

What is an effective potential in classical mechanics? I have read the wikipedia article and David Tong's lectures notes, but I didn't understand how an effective potential simplifies a situation or ...
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Are there any fully analytically solvable nonlinear oscillators?

I'm trying to find a simple one-dimensional problem, in which a particle would oscillate with some energy, and the period of oscillation would depend on particle energy (unlike in harmonic oscillator)....
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Partition function of a 3D vibrating string

Is the partition function of a 3D vibrating string a sum of discrete energies, an integral of an energy continuum, or both? $$Z_{\text{disc}} = \sum_{k=1}^{\infty}g_ke^{-\beta E_k}$$ or  Z_{\text{...
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Why does a wind turbine have only three blades? [duplicate]

Why not four or five or even more? Intuitively, the more leaves the more power. So, what is the reason?
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Free rotation of a rigid body

So I am currently reading Fowles and Cassidy and there is something I'm confused about in the section about geometric description of free rotation of a rigid body. I will present the stuff first that ...
Consider a Lagrangian $L(q_i, \dot{q_i}, t) = T - V$, for kinetic energy $T$ and generalized potential $V$, on a set of $n$ independent generalized coordinates $\{q_i\}$. Assuming the system is ...