All Questions
15
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Dynamic equilibrium of planets
We can describe statical equilibrium ( forces, moments ) in a cuboid $$ \Sigma F_x=0,\Sigma F_y=0,\Sigma F_z=0~$$ In dynamics can we describe similar dynamic equilibrium within an inertial ...
- 1,032
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1
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Physics of a falling body within a spherically uniform system [duplicate]
I was reading The First Three Minutes and in the book it talked about how if a stone fell in a cave deep in the Earth we could calculate it's motion as if the surface of the Earth is the surface of ...
- 38
1
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3
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319
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What would happen if the Earth was hollow and somebody rode on the "inside shell"?
I'm having a difficult time understanding basic centripetal force, forgive me. On the earth as it currently is, if you fall off a cliff you will fall closer to the core. However on a cylindrical ...
- 23
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1
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69
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Will the weight further increase while going inside the Earth? [duplicate]
Our weight is more at the pole than at the equator (because it is closer to the center).
Does that mean if we go down into the earth (some kind of bore), will our weight increase further?
I remember ...
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1
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1
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Gravitational Field Strength of a point in between Two Planets
In my textbook, under the topic of gravitation, it states that if the centres of 2 planets, each of mass $M$ and separated by a distance $r$ and you have a point halfway between the centres of the ...
- 113
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4
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140
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Doubt when calculating the gravity force excerted by a planet to an object on its surface
I have been thinking about why when you want to calculate the gravity force/acceleration that a planet exert on a obect, it is considered that all the planet's mass contributes to create a vertical ...
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3
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409
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Why are planets not torn apart?
There are two forces we know, Centripetal force (or Gravity) and Centrifugal force. Both are applied to all the planets including earth. Planets are kind of spherical due to gravitational force but ...
- 413
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1
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Why can we not take gravity to act at the center of mass in this case? [closed]
I found this problem when I was trying to prove that the gravitational attraction on an object is the gravitational attraction on the center of mass of that object (I had doubts on it). And in doing ...
- 1,189
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2
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123
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Is there a smooth transition from inverse quadratic gravity to linear gravity?
I can't remember exactly what it was, but I remember going through a problem in physics related to gravity on and inside a sphere, and found that inside, gravity acts linearly as a result of some ...
39
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12
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If gravity disappeared, would Newton's third law make everything that was pressed to the ground by gravity get pushed upwards? [closed]
If gravity disappeared, would Newton's third law make everything that was pressed to the ground by gravity get pushed upwards?
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1
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315
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Is it mathematically accurate to simply objects to point masses when calculating gravitational forces between them? or is it just an approximation?
I tried searching for the exact mathematical proof that validates this assumption, but I couldn't find any.
Also, is this assumption still accurate if the density of the object resembles a planet (...
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2
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Why don't heavenly bodies attract each other stronger? [duplicate]
In my physics textbook, it's written that
According to the laws of gravitation force,
all masses attract each other
the greater the masses, the stronger the pull
the closer the masses, the stronger ...
- 113
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4
answers
2k
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Pressure and gravity at the center of the earth
I apologize if this sounds stupid, but as someone without a lot of physics training I was wondering...Regarding gravitational forces, since it is this that brings the dust and rocks together to form ...
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2
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3
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2k
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Two bodies of finite size treated as two point masses in Newtonian gravity
When discussing gravitation between two bodies of finite size, for instance Earth around the Sun, we suppose the mass of Earth and the Sun to be perfectly localized at the center of each body. Is this ...
user60924
3
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1
answer
261
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How should I be thinking about tides?
I am working on a project for physics that involves tides. This is my current mind set when thinking about tides:
The earth applies a gravitational force on some mass ...
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