All Questions
Tagged with classical-mechanics reference-frames
204
questions
2
votes
4
answers
228
views
Is angular momentum conserved on a spinning sphere, specifically Earth [closed]
Specifically in relation to meteorology. I was wondering if the angular momentum an object, lets say a parcel of air has due to the roation about the earths axis. Is it conserved if moved to a ...
- 2,821
2
votes
3
answers
466
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Why isn't frame of reference called reference point? [closed]
A frame of reference is the perspective you have on a happenstance. But isn't it a viewpoint or point of view? As in, a literal point, from which something is observed?
If so, why is it called a frame ...
2
votes
1
answer
171
views
Why is this hamiltonian not the energy? [duplicate]
Let a pendulum of length $\ell$ be connected to a rod that rotates with constant angular velocity $\omega$. $\theta$ is the angle of the pendulum wrt $z$ axis ($z$ axis is parallel to the rod).
I ...
- 21.9k
2
votes
2
answers
143
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Why is simultaneity a requirement for the distance function of Galilean space?
At the end of Chapter 2 of his Course in Mathematical Physics, Szekeres discusses the notion of a symmetry group. I present my definition, adapted from his, here:
We say that a transformation $g: X \...
- 70.2k
2
votes
1
answer
267
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Having trouble deriving the exact form of the Kinematic Transport Theorem
The Kinematic transport theorem is a very basic theorem relating time derivatives of vectors between a non rotating frame and another one that's rotating with respect to it with a uniform angular ...
- 1,427
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votes
1
answer
142
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Correct Lagrangian for classical central force problem?
Wikipedia gives the following Lagrangian for central force problem:
$$\mathcal{L}=\frac12 m \dot{\mathbf{r}}^2-V(r)$$
where $m$ is the mass of a smaller body orbiting around a stationary larger body. ...
- 13.8k
0
votes
3
answers
106
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Angular momentum of $N$ particles
I am reading Goldstein's Classical Mechanics book; I have difficulty understanding these lines. Why do the last two terms vanish? I am reading this and thinking $r'$ is a null vector, but the second ...
1
vote
2
answers
150
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Is work done relative according to the theory of special relativity?
I performed a thought experiment.
Consider a body $A$ and another body $B$.
Body $B$ is moving at velocity $v$ in direction $x$ with respect to $A$. This implies that body $A$ is moving at velocity $v$...
- 1
0
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5
answers
1k
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Do released objects take the direction and speed of their parent frame's velocity, or just the parent frame's speed component?
Context: I'm working on a space game. I noticed that an unpowered object fired from a strafing spaceship appeared, as the released object moved, to curve in the direction the ship was strafing. This ...
- 8,833
0
votes
1
answer
35
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Center of Mass calculation in configuration of $3$ pennies inscribing equilateral triangle [closed]
I'm working on a problem that is asking me to solve the moment of inertia about the center of mass of a $3$ penny system where the edge of each penny is touching the edge of the others and the ...
- 56.5k
0
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4
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2k
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Why is a reference frame moving with constant velocity with respect to an inertial frame also inertial?
We define an inertial frame, as a frame of reference where:
Newton's 1st law holds.
It is then stated that a reference frame moving with constant velocity with respect to an inertial frame is also ...
- 25k
0
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5
answers
160
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Torque Intuition [duplicate]
We are all taught that the torque $\boldsymbol{\tau}$ is given by $\boldsymbol{\tau} = \mathbf{r}\times\mathbf{F}$ so that torque increases with the lever arm length. What is the physical intuition ...
- 1,232
1
vote
2
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737
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Center of mass in hydrogen atom
I have few questions regarding quantum treatment of the hydrogen atom problem.
Why does one changes coordinate from position vector of electron and nucleus to COM coordinates and relative position ...
- 5,578
1
vote
1
answer
92
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How to define differentiation of a time-dependent vectors with respect to a specific reference frame in a coordinate-free manner?
It is usual in classical mechanics to introduce the derivative of a time-dependent vector with respect to a reference frame. This is accomplished through the use of a basis that is fixed with respect ...
0
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1
answer
44
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In terms of which zero should i calculate the potential energy in the Lagrangian formalism?
What I understand is that we have two kinds of coordinates when working with the Lagrangian formalism with different zeros (which may happen to coincide) to measure from, those are the Cartesian ...
- 5,389