All Questions
Tagged with dynamics or newtonian-mechanics
21,832 questions
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Has someone ever obtained a relative trajectory being exactly the Coriolis formula without a background centripetal force (as gravity)?
In geophysics and many other cases, the Coriolis formula is clearly linked to a background centripetal force.
Read Anders Persson (UK MetOffice, EU ECMWF, Sweden SMHI, Uppsala) https://scholar.google....
2
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1
answer
195
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Orbiting ring vs orbiting body
A solid ring cannot orbit a mass at its center because it is in unstable equilibrium, and a slight perturbation would cause it to drift.
An object obviously can orbit. You can also take a portion of a ...
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17
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When i'm trying to resolve this problem or any similar problem about rotation, do the starting position need to be negative? [closed]
A material point A, starting from rest at the position shown in the figure, moves counterclockwise with uniformly accelerated motion.
At the same time, from position B, another material point M₂ ...
user556380
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0
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I need help on a conceputal problem for kinetic friction problem [closed]
If the coefficient of friction were to increase, how would this affect the total travel time? Explain why by referring to both intervals of motion. Use at least one physics representation as part of ...
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Finding correct tension in simple pendulum [closed]
Please forgive me if I am being too much stupid. But please can anybody tell me why I am getting two different values of the Tension for the same pendulum. Its not at equilibrium. As it oscillate due ...
2
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0
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47
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Is it possible to balance yourself on one static wheel? [closed]
A friend and I are trying to understand how to think about the following scenario. Consider a person on a unicycle on flat ground, with a blocked wheel (the wheel cannot rotate relative to the axle). ...
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1
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74
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How does the relativistic action logically follow from the nonrelativistic action, and why is proper time involved? [closed]
In nonrelativistic mechanics, the action for a particle of mass $m$ moving in a potential $V(\mathbf{x})$ is
$$
S_{\text{classical}} = \int \left(\frac{1}{2} m \mathbf{v}^2 - V(\mathbf{x}) \right) dt.\...
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1
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38
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Center of mass of 3d object [closed]
A box is open at the top in the form of a cube of edge length 40cm, is constructed from thin metal plate. How do I find the center of mass of the box with respect to the coordinate system where the ...
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3
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519
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A question on the nonrelativistic limit of special relativity [closed]
In special relativity, one typically works in the spacetime manifold with the Minkowski metric:
$$ds^2=-c^2dt^2+d\vec x^2.$$
However, I find it intuitive that in the nonrelativistic limit, if one also ...
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2
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Will a frictionless rope in space retain its shape if all segments move tangentially with equal velocity?
Suppose we have a uniform, massive, flexible, frictionless and non-stretchable rope in space, initially shaped arbitrarily. Each infinitesimal segment of the rope is given the same velocity in the ...
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1
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Can gravity make an infinite amount of energy? [closed]
If we use gears, then we put a long metal stick then put a $100\text{ kg}$ metal object on it, assuming there are $200$ gear and each has a ratio of $1:5$, because a larger section of the double gear ...
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0
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58
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Help with car physics [duplicate]
I've been trying to work on a car in a game, of course, this is a physics forum and my question is how does a car torque and angular velocity even work?
Consider this, a user pressed the W key and the ...
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1
vote
3
answers
105
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Newton's 2nd Law [duplicate]
We know:
$$ F = \frac{dp}{dt} $$
and:
$$p = mv$$
so by simple calculus, is it correct to write:
$$ F = m \frac{dv}{dt} + v \frac{dm}{dt} $$
If not, why not?
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5
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458
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Football rolling down a hill
I rolled an American football down a gentle slope of about 10°. Regardless of how I started it, after some distance, it tended to roll around the short axis ($y$-axis). I expected it to roll around ...
- 407
1
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1
answer
106
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Interpreting one-dimensional Newtonian mechanics using complex numbers? (via Hamiltonian mechanics)
Let the configuration space of a single "point particle" be the one-dimensional affine space $\mathbb{A}^1 \cong \mathbb{R}$, with a chosen linear coordinate chart identifying some ...
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2
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65
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How are the force expressions (body weight, additional weight, and buoyant force) formulated and related in a fluid statics problem?
In fluid dynamics class, I saw a statics problem that dealt with buoyancy using Archimedes’ principle. The problem stated the following:
A wooden plank with a cross section of 7.5 cm × 30 cm and a ...
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1
answer
94
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Bucket rotated in a vertical plane [duplicate]
This was a "give the reason" question in my textbook.
If a bucket containing water is revolved fast in a vertical plane, the water does not fall even when the bucket is completely inverted.
...
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7
answers
552
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How can the work-energy theorem be applied in case of a block impacting a massive spring?
We have a spring with uniformly distributed mass $m$ and stiffness $k$, with free length $x_0$ aligned with the $x$-axis, lying on a friction-less table. A block of mass $M$ is moving towards it along ...
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5
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86
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Can a short, strong increase of normal force make a sliding block reverse direction on a fixed surface?
A block is sliding to the right on a horizontal, stationary platform. For a very short time I press straight down on the block so the normal force—and therefore the friction—briefly becomes large. I ...
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23
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Book recommendations for relearning dynamics and static (mechanics) [duplicate]
When I first took courses in dynamics and statics (they were part of an applied mathematics track rather than physics), I didn’t really appreciate them and only studied enough to pass. I also didn’t ...
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1
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57
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Velocity of approach equal to velocity of separation?
Can we say that the velocity of approach is equal to the velocity of separation here?
I saw this being used in a problem. From what I understand, this result was derived for two particles undergoing ...
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3
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80
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Doubt in conservation of momentum in perfectly inelastic collision in different frames [closed]
If body A1 is at rest and another body B1 is approaching towards it and they have perfectly inelastic collision collision . So how in frame of body A1 that was at rest say that momentum is conserve ...
2
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1
answer
202
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Equation of motion of a point sliding down a parabola [closed]
I have a frictionless parabola $ (t,t^2) $ on the $x,y$ plane. I was having difficulties deriving the equations of motion for a point P placed at a height h on the parabola and let go of without any ...
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1
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149
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Does this spring work with Hooke's law or not? [closed]
In the table is the data from the spring. In the y axis is the force in Newtons, and in the x axis is the extension in meters.
Edit: I found out the reason why this spring did not work as initially ...
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0
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109
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Why do we have a horseshoe curve in this railway section on only one track?
Just north of the Ponpadi station on the Chennai-Renigunta railway line lies a breathtaking horseshoe curve:
I am quite aware of the reason why horseshoe curves exist on railway lines, due to the ...
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