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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Solenoidal forces

As far as I know a solenoidal vector field is such one that $$\vec\nabla\cdot \vec F=0.$$ However I saw a book on mechanics defining a solenoidal force as one for which the infinitesimal work ...
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Can cyclic acceleration/deceleration be worse for fuel consumption?

Recently I have started to drive my car slower on the highway in order to save money on gas. However, I feel like I am spending at least as much fuel as before. One possible explanation that I thought ...
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Does vehicle tire mass effect efficiency?

This question has an interesting origin: A tire salesman was recommending tires (aka tyres) for a highly fuel-efficient vehicle. He said the vehicle was light (compared to most production cars), and ...
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Isolated system and mutual interaction potential

We know that the total linear momentum of a closed (isolated) system is conserved due to homogeneity of space (Landau and Liftshitz, page 15, Mechanics). Hence for an isolated system of two bodies ...
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Does a ball thrown down exert less force on the ground when we walk? [closed]

Scenario A: You stand still and throw a ball vertically down. When the ball hits the ground it exerts a specific force on the ground. Scenario B: While walking you throw a ball vertically down. When ...
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How can we tell the potential from the orbit?

The orbit is $$r(θ) = a(1+\cos θ).$$ The orbit of the particle is in polar coordinates. How can we tell the potential $U(r)$ from this? $U(r)$ goes to zero at infinity.
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Cylinder rotating without slipping on an accelerating slab [closed]

I am very confused by the following problem asked in my first year physics class: Please let me know if you can assist in any way! I've spent hours and hours on this question and gained absolutely ...
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Relation between linear and rotational motion of molecules?

The temperature of a substance, such as an ideal gas, can be related to the root mean square speed of the molecules. For example, for gases the molecules travel at about 480 meters per second. If we ...
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Conversion of angular momentum to linear momentum in free space

If two objects both with angular and linear velocity collide in free space, can the total linear velocity of the objects increase at the expense of a loss in angular momentum? In other words, imagine ...
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Torque and Force of Pulley fixed on side

If you had only 1 pulley that is connected to a rotating shaft, and which has a rope circled around it once, with a mass M on one side and with the rope fixed on the other end, how would you then ...
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Coordinates from action-angle variables

I'm interested into getting the original coordinates, $q(t)$ and $p(t)$, from the action, $J=\oint p dq$, and angle, $w(t)=\frac{dH}{dJ}t+\beta$, variables for a 1-D, one particle system. I know that ...
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Confused about something in Landau classical mechanics

On page 7 in Landau and Lifshitz Mechanics He writes: We have $L'=L(v'^2)=L(v^2+2ve+e^2)$ now the confusing part comes (for me): He writes: Expanding this expression in powers of e and neglecting ...
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Lagrangian Mechanics + Account for friction of block

$\newcommand{\dd}{\mathrm{d}}$ I am trying to work out the Lagrangian mechanics for a pendulum problem in order to animate it. I'm working on one of the examples in the Wikipedia page on Lagrangian ...
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Ultrasound Transducers and Simulator [closed]

Presently I am working on Underwater Acoustic Wireless Transmission. I desire to measure water parameters at the bottom of the surface of the water and then pass it to the water surface using ...
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heap of pebbles

It is common to see a heap of conical shape formed by a large number of similar size hard spherical objects, for example, a heap of pebbles, sand etc. Suppose we want to model this system as a ...
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Simplest Live Demonstration of Adiabatic Transport

I have to give a presentation on Berry phase. I would like to give the simplest live demonstration of adiabatic transport. If I move an object in a loop and return that object back into its original ...
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All I could find about pendulums assumes that the force on the pendulum mass m is mg directed downwards. The case of m being attracted only by the radial gravity pull (thus replacing the "plane" ...
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Lyapunov stability of circular orbits

I'm studying Classical mechanics on Arnold's "Mathematical Methods of Classical Mechanics". In a problem i'm asked to find for which $\alpha$ the circular orbits in the central field problem are ...
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Are these torques correct for a simple balancing/fulcrum experiment?

For my physics lab, they had us do a simple static equilibrium experiment where we rested a ruler on a fulcrum (at its center of mass) and then attached varying amounts of weight on either end at ...
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Are there any conditions under which the Christoffel symbols can be treated as a damping term in a harmonic oscillator?

(Mathjax did not seem to be working as I composed this question. Hopefully it will kick into action once I post.) Note I am a novice at tensor notation. I am working with the following Lagrangian (...
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Calculating car engine RPM from inputs [closed]

So I am willing to calculate engine RPM of car. The usual process for doing this in games is: $\omega_\mathrm{e} = \omega_\mathrm{w} * D_\mathrm{k} * g_\mathrm{k} * 60 / 2\pi$ However, this ...