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; ...

learn more… | top users | synonyms (1)

0
votes
0answers
13 views

Examples of using more advanced maths to simplify physics problems and provide better insights? [on hold]

I'm trying to collect examples of using more advanced maths to describe physics and especially when the new mathematical tool can help to provide a better understanding. An example is the use of ...
0
votes
1answer
33 views

What are the proper unit types for the calculation of the frequency of a tuning fork?

Wikipedia Article on the subject The formula states that the calculation of the frequency with cylindrical tines should be $$1.875^2/(2\pi L^2)\times(Er^2 /(4P))^{1/2}$$ where the variables are ...
1
vote
1answer
64 views

Newtonian motion of a particle confined to a smooth surface

Recently, I've been considering a model wherein a lone particle with constant mass m is confined to a surface $F$: $\mathbb{R}^m \to \mathbb{R}^n$ , where $m < n$. I declare this surface to be ...
1
vote
1answer
45 views

For infinitesimal Canonical Transformations, what functions are allowed for this to be a canonical transformation?

Consider two infinitesimal transformation: $$q_{i} \rightarrow Q_{i} =q_{i} + \alpha F_{i}(q,p) $$ $$p_{i} \rightarrow P_{i} = p_{i} + \alpha E_{i}(q,p) $$ where $α$ is considered to be ...
0
votes
0answers
22 views

Can a nozzle increase the thrust of a water rocket?

First of all, what is the correct equation to determine the thrust produced by a water rocket? $F_T = ṁ * V_e$ (1) $F_T = ṁ * V_e + (p_e - p_0)A_e$ (2) Using the first equation it should be ...
0
votes
1answer
57 views

Consistent method for finding direction of static friction

I am having trouble coming up with a consistent method of determining the direction of static friction. So far the best I have come up with is: it should oppose the relative acceleration the contact ...
0
votes
1answer
39 views

A metal block in a tub of frictionless ball bearings

If you place a metal block in a tub of small frictionless ball bearings of the same metal, would it stay on top or sink?..
4
votes
2answers
44 views

How does rotational energy transfer to linear energy?

So I have recently started looking into moments of inertia, and all that stuff. I have come to a question which has a plane inclined at some angle theta and a sphere at the peak. The G.P.E at the top ...
1
vote
4answers
82 views

Why spinning a pen makes it easier to remove it from the stand?

I have a ballpoint pen stand on my desk. The pens are held inside their caps with the point down, like this one (but not as fancy): If I try to simply pull up one pen, the friction between cap and ...
-1
votes
2answers
35 views

Why do motorcycles have bigger wheels than mopped? [closed]

I am from India. Here bikes and mopeds are used almost everywhere for the same purpose and terrain.
1
vote
3answers
76 views

Formulating the Lagrangian in terms of invariant quantities

Consider a closed system consisting of $N$ point particles, whose Lagrangian is given in the standard way, by the total kinetic energy minus the potential energy: $\mathcal{L}(\dot{q},q):= T(\dot{q}) ...
4
votes
0answers
50 views

Driven Pendulum

If the point of suspension of a pendulum is driven periodically in the vertical direction , we can derive the equation of motion for the suspended mass to be of the form, $\ddot{\theta}(t) + ...
-1
votes
2answers
49 views

Formula or relation for forcing spring movement over a certain time (as the image shows) [closed]

i have explained my objectives in the image the fact is i'm planning to use such motion in programming but i have some serious trouble over controling the time that this motion finishes! what i'm ...
1
vote
2answers
107 views

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 ...
1
vote
2answers
125 views

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 ...
-4
votes
1answer
40 views

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 ...
0
votes
0answers
7 views

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 ...
0
votes
1answer
35 views

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 ...
1
vote
2answers
269 views

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 ...
1
vote
1answer
94 views

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?
0
votes
2answers
88 views

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 ...
1
vote
1answer
50 views

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?
0
votes
1answer
31 views

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 ...
0
votes
0answers
19 views

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 ...
3
votes
2answers
73 views

What can be inferred about this particle from a Lagrangian?

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?
0
votes
0answers
47 views

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 ...
0
votes
1answer
25 views

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 ...
1
vote
1answer
45 views

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.
2
votes
0answers
26 views

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 ...
7
votes
3answers
185 views

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?
0
votes
2answers
38 views

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 ...
1
vote
1answer
80 views

canonical ensemble that is quantum mechanical and continuous?

I do not understand what the following statements from Wikipedia mean For a canonical ensemble that is quantum mechanical and continuous, the canonical partition function is defined as $$ Z = ...
6
votes
0answers
57 views

Why is this handle flipping back and forth? [duplicate]

This gif of some kind of handle being spun in zero gravity has been doing the rounds: Why is it flipping back and forth? It seems odd that it flips, then seems to rotate around one axis in a ...
3
votes
0answers
42 views

What variable is the conjugate momentum for angular momentum?

From the definition of conjugate momentum for a generalized coordinate we get that the conjugate for angular momentum should be proportonal to its integral with respect to time. According to my ...
0
votes
1answer
101 views

Example where Hamiltonian $H \neq T+V=E$, but $E=T+V$ is conserved

I'm looking for an example of a Hamiltonian $H$, where $H\neq T+V$, but the total energy in the system, $E=T+V$, is still conserved. While I'm at it, I might as well add that I'd be most interested ...
1
vote
0answers
11 views

Is there an analog to the Runge-Lenz vector for a harmonic potential?

The Runge-Lenz vector is an "extra" conserved quantity for Keplerian $\frac{1}{r}$ potentials, which is in addition to the usual energy and angular momentum conservation present in all central force ...
0
votes
0answers
23 views

Central Force Scattering in Goldstein

On page 108 in Goldstein 3rd edition in the paragraph after equation (3.94) he says that $\psi$` can be obtained from the orbit equation (3.36) using the limits as $r_0=\infty$ $r=r_m$ which the ...
3
votes
3answers
112 views

Where does the $(\ell + x)^2\dot\theta^2$ term come from in the Lagrangian of a spring pendulum?

I am reading some notes about Lagrangian mechanics. I don't understand equation 6.9, which gives the Lagrangian for a spring pendulum (a massive particle on one end a spring). $$T = ...
5
votes
2answers
302 views

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 ...
0
votes
0answers
37 views

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 ...
2
votes
2answers
64 views

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 ...
6
votes
3answers
269 views

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. ...
6
votes
1answer
77 views

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 ...
0
votes
1answer
42 views

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 ...
1
vote
3answers
108 views

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 ...
-2
votes
2answers
95 views

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 ...
2
votes
1answer
76 views

How does a tightrope walker return to equilibrium?

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 ...
0
votes
0answers
49 views

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 ...
0
votes
0answers
18 views

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 ...
0
votes
0answers
25 views

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?