# 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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### Probability of observing harmonic oscillator at a particular position

Consider a classical harmonic oscillator whose Hamiltonian is $$H=\frac{p^2}{2m} +\frac{1}{2}mw^2x^2$$ where $w$ is the oscillating frequency. I wish to find the probability of observing the harmonic ...
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### How do I approximate an angular acceleration vector from a history of orientations?

A rigid body is simulated to move in six degrees of freedom. At every past timestep, I know its displacement vectors $x^{GLOB}$ in the global coordinate frame, as well as 3x3 matrices $R$ that ...
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### Question about constraint in lagrangian

We know that the lagrangian can be written using constraints. Suppose I have constraint functions $$f_1=\cos(x) - (x+t)/R=0,\qquad f_2=\sin(x)-y/R=0 .$$ But I know that $1=\cos^2+\sin^2$, so do we use ...
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### Can a frame still be an inertial frame if its center varies with time relative to a “true” inertial frame?

Picture a seat on a Ferris wheel. Neglecting any rocking, is the seat of a Ferris wheel an inertial frame? My guess is that yes it is right? The frame itself isn’t rotating or accelerating relative to ...
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### Does passing an electric current along a strip of metal submerged in saltwater cause anything?

If saltwater corrodes metal. Can we effectively stop this by passing some electric current? Has this been tried before?
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### Is there a way to understand which variable is more influential in the dynamics of a system?

Is there any known way to identify which variable has the most impact in the dynamics of a system given its lagrangian or hamiltonian formulation? Let's say i have a system with 3 variables, two ...
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### Finding a new hamiltonian from a given canonical transformation

Let us suppose we have a given Hamiltonian $$H = \frac{P_1^2}{4}+\frac{P_2^2}{2}+V(Q_2)$$ and $q_1 = Q_1 + Q_2/2$ with $q_2 = Q_1 - Q_2/2$. I need to find the new hamiltonian by using these canonical ...
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### Help with understanding virtual displacement in Lagrangian

I know that these screen shots are not nice but I have a simple question buried in a lot of information My question Why can't we just repeat what they did with equation (7.132) to equation (7.140) ...
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