日本核心消费价格指数连续14个月走高
百度 诚然，为完成工作的适度加班应当鼓励，部分工作因工作性质也不得不加班，但变加班为“假班”，则是形式主义的新表征，应该重点整治。
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].
25 questions from the last 30 days
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Who makes most effort when two people of different heights lift a table?
There are two people lifting a table of length $l$. One is short the other one is tall. The table is solid so its center of mass is therefore at the center of the table. Since the two people are of ...
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Engineering mechanics basic question? [closed]
Thdbsvdbfbtjjrjfhrhhrhrhr zvzbdbdbdbdbdbdbdbdvdvdvdvrgrg wtgegdgdg egegege rbdbdg egegdgd egddvr rvdgdg gegdvs egeg
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58
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Gauging a Symmetry in Classical Mechanics
I'm trying to understand the meaning of gauging a rigid symmetry from the first order formalism of classical mechanics.
Consider the action
\begin{equation}
S[p,q]=\int dt\left\{p_{i}\dot{q}^{i}-H(p,q)...
- 3,187
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28
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Phase line and its configuration space
If I consider a system represented by a phase line or a one dimensional phase space, which is the configuration space? Is the dimension of the configuration space zero? Can I consider this phase line ...
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71
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What is the current status of the ergodic hypothesis? [duplicate]
According to Wikipedia, Boltzmann's ergodic hypothesis says that, for the systems of interest in statistical physics,
over long periods of time, the time spent by a system in some region of the phase ...
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63
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Variations with Non-Holonomic Non-Integrable Constraints
I am reading this paper by Flannery. He considers a non-holonomic non-integrable set of constraints
$$g_k=g_k(q_i,\dot q_i,t)=0, \quad k=1,\ldots,c,\tag{3.1}$$
where the $i$ index runs to $n$. He ...
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Is it still a shear deformation if all layers of the body move in different directions? [closed]
I'm trying to formulate a definition of shear deformation, but couldn't find any that accounts for all edge cases.
I know what it is, but I can't describe it without a ton of examples.
All definitios ...
- 99
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127
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Is really the quantum micro-world that is "weird" or is it because our man-made Quantum Mechanics we use is a nonphysical model? [closed]
The problem is the effective model QM maths we use which fails to describe physically (real) the quantum micro-world as it is? It is not the quantum micro-world that is weird but it is due to the ...
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1
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Can a straight and smooth object at rest have a wavy/curved shadow?
There's an object (partition between windows), whose shadow falls upon a curtain inside the room. However , the curtain is not still , it's moving (due to interaction with air) due to a fan working ...
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How does the Drude model justify using drift velocity as a steady-state flow speed, even though it is derived as an average final velocity at the tim? [duplicate]
? How Can Drift Velocity Be Considered Constant When It's Defined Only at the Instant of Collision?
I'm trying to reconcile two ideas in the Drude model of electrical conduction:
We often define the ...
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Why did Bohr assume circular electron orbits, despite inverse-square forces allowing elliptical ones? [closed]
In Bohr’s model of the hydrogen atom, electrons are assumed to orbit the nucleus in circular paths under the Coulomb force. However, under inverse-square law forces (like gravity or electrostatics), ...
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1
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Dissipation and Fundamental Forces
In newtonian mechanics, forces with a time or velocity dependency will not conserve energy in general, does this mean they are just effective forces used to describe problems with high complexity? Or ...
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54
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How was power transmitted to gyroscopes while in use? [closed]
In the example gyroscopes I have seen, they are all spun up while held stationary.
For GNC (Guidance, navigation, and control) applications the gyro needed its speed to be maintained over time while ...
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1
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Derivation of Hamiltonian [duplicate]
In quantum mechanics, is the definition of the Hamiltonian $H = T + V$ just an educated guess rather than something that's derived?
In classical mechanics, the Hamiltonian $H = T + V$ makes intuitive ...
2
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1
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162
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How does one incorporate moving frames in the model of universe as an 4 dimensional affine space?
From what I understand, in relativistic and non-relativistic mechanics, we model the universe as an affine space $(E,\vec{E},-)$ where $E=\vec{E}=\mathbb{R}^4$. An orthogonal cartesian coordinate ...
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