All Questions
Tagged with equilibrium newtonian-gravity
37
questions
4
votes
1
answer
190
views
Gravitational Null Points in a system of point masses
For an equilateral triangle formed by 3 point masses which has a circumradius 'a' there are 4 null points: The centroid and 3 other points on the angular bisectors of the three sides.
On calculation ...
0
votes
2
answers
55
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Direction of the normal force [closed]
Suppose we have a bar with non-zero mass inside a hemispherical bucket fixed to the ground. Suppose, too, that there is friction between the bar and the inner spherical surface of the bucket. Part of ...
0
votes
0
answers
49
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When calculating Lagrange points, $L_3$, $L_4$ and $L_5$ are good, but why are my $L_1$ and $L_2$ too close to the Earth?
I'm using python to calculate the Lagrange points of the Sun-Earth system. I started assuming that - for $L_1$ at least - the sum of the gravitational acceleration towards the Sun and the centripetal ...
- 111
1
vote
2
answers
197
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What is the total energy of newtonian polytrope stars of index $n > 5$?
In classical newtonian theory, we could find a general expression for the gravitational potential energy of a polytrope sphere (of pressure $p(\rho) = \kappa \rho^{\gamma}$, where $\gamma = 1 + \frac{...
- 7,592
0
votes
2
answers
75
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Equilibrium of differential mass element of a homogeneous rod hanging from ceiling
I was solving a question that asked me to find the change in length of a rod when it is hung from the ceiling. When I saw the solution, they took some differential elements and said that a force due ...
- 265
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2
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47
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Lopsided planet
Something that has always puzzled me about Pangaea.
If we have a "roughly" spherical mass of solids, aren't two points on opposite sides approximately the same distance from the center of ...
- 369
3
votes
3
answers
668
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Why does a uniform flexible rod sag?
Imagine a long flexible rod with uniform mass. The rod is supported by a pivot at its center and it is at equilibrium. How do we explain why the rod sags at the far ends?
If we attempt to draw a free ...
- 568
0
votes
1
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89
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Why everything wants to come into its lowest state of potential energy and why there manybe more than one position of stability?
Suppose we have a solid hemisphere , one can observe that from both curve and flat surface is kept on ground it acquires a stable position on its own , why its does so ? And if its true then why not ...
- 117
0
votes
2
answers
552
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An elevator moving with constant velocity
While an elevator moves up, it moves up with a constant velocity. I read this post and understood that it's because of inertia. However, I'm not really convinced.
So what happens which I have ...
- 1,168
0
votes
3
answers
381
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Maximum extension in spring
Suppose a mass $m$ is attached to a spring. Now if the mass is released, the tension will be the restoring force of the spring and since the mass is neither going up nor going down, we have $kx=mg$ or ...
- 1,179
2
votes
0
answers
56
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Are there methods to determine the equilibrium points of the general three bodies problem?
Starting from the three second-order differential equations, I have written the problem in the form of a system (from a modelling point of view): $$\mathbf{\dot{x}}=\mathbf{f(\mathbf{x})}$$
where $\...
- 768
17
votes
14
answers
17k
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Why do rain drops fall with a constant velocity?
While reading my physics book. I came across a line that says that:
Rain drop falls with a constant velocity because the weight(which is the force of gravity acting on body) of the drop is balanced ...
user315348
0
votes
3
answers
631
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Why is the normal force and the tension force greater than the weight in these examples? [closed]
A pendulum is suspended form the roof of an accelerating train. If it stays in equilibrium with respect to the train then an observer at rest will find the bob accelerating with the train. He will ...
- 49
1
vote
3
answers
228
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Tension and force equilibrium analyzed via Newton's laws of motion
I was recently solving my workheets to apply basic concepts of Newtonian mechanics. I came came across the following problem.
The above is under equilibrium. The solution the book gave me was as ...
1
vote
1
answer
472
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If Earth is oblate why don't oceans flow to the Poles? [duplicate]
The Poles are ~21 km downhill from the equator in a spherical coordinate system.
So why doesn't water pool there?
- 182