# Tagged Questions

The Newtonian model of gravity in which the force between two objects is given by GMm/r^2.

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### Is it possible to build planet-sized non-spherical structures?

Beyond certain size and density the celestial objects tend to admit a spherical size. I wonder if is there a fundamental mass, density or specific strength related number which when surpassed a non-...
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### How to compute Gravitational potential energy

Find the potential energy of a system of four particles placed at the vertices of a square of side $\ell$. Also obtain the potential at the centre of the square. In the question above can ...
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### Why does mass not matter on how quickly an object falls? [duplicate]

I've seen all the mathematical proofs and physics demonstrations in vacuums. However, for example, if a hammer falls to the Earth it falls very quickly. But, it can be interpreted another way. The ...
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### Why does using the modified Kepler's 3rd law and using the gravitational parameter yields different results?

$p^2=\frac{2\pi a^3}{\mu}$ ($p$ is the orbital period in seconds) gives slightly different result from $p^2=\frac{4\pi^2}{GM_1}a^3$.
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### Units in gravitational N-body simulations

I use a code in Python to simulate a binary system interacting through gravity. You can find it here; The code works fine. I am however having problems with the units of length and velocity. I ...
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### What is the easiest way to experimentally determine the center of mass of an irregular 3d object that has a non-uniform density?

I want a method that can be done in a basic high-school lab.
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### Are we increasing the gravity of Earth with our population?

I have these questions related to my question title: Do we, other species and things have our own gravity? How much Gs a human have? Are we effecting Earth, nearby moons and planets with our gravity?...
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### Moon Gravity Vs Earth Gravity Pull

Sometime in the near future, I developed an experimental superweapon capable of blowing up the entire moon, I use it and the blast breaks the moon into multiple pieces of varying sizes. So now we have ...
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### Will the object spin as the earth spins?

If an object is designed to levitate a few kilometers above the ground, and the point directly below the object on earth is called $A$, as time passes and the earth rotates about its axis, will the ...
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### Why are triangles drawn like so when working with gravity on an inclined plane?

This is my first year as a physics student, and I've never learned about vectors past a basic level, so this is confusing me. When we have gravity on an inclined plane, we separate it into two ...
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### Does $v^2=v_0^2-2gh$ work if the positive axis is up and the initial velocity is down?

In the situation where the positive axis is up, the acceleration due to gravity is $g$, and the velocity is represented by the equation $v^2=v_0^2 - 2gh$. This works great if the initial velocity is ...
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### Why aren't Roche limit and the difference in gravitational acceleration the same?

The definition of the Roche limit is: "The distance within which a celestial body, held together only by its own gravity, will disintegrate due to a second celestial body's tidal forces exceeding the ...
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### How far inside a white dwarf Roche limit does the Earth have to be to start losing large chunks of rocks?

I have calculated that for a one solar mass white dwarf orbited by the Earth, the Roche limit is about 600,000 kilometers. I understand that any loose mass on the surface of the Earth would start ...
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### What mistake am I making in plotting this graph of effective potential for the Earth-Moon system?

I am trying to create a graph of effective potential for the Earth-Moon system in Excel. It should result in a graph that looks like this: But this is not what I end up with. (I've made a Google ...
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### Newton's shell theorem in 2d [closed]

I was wondering how to prove the analog of Newton's shell theorem for 2 dimensions, in which gravity obeys an inverse-linear law. Meaning: that an anywhere inside a circle, the gravitational field ...