<p>Classical mechanics approach to this would be <strong>gravitational force</strong> as we know <code>F=GMm/r2</code> and <strong>Centripetal force</strong> <code>F=mv2/r</code>.</p>

<p>In free space we when two things are kept some distance apart they accelarate towards each other (along straight line from center of on body to center of another body) due to force of gravity but if they are under some influence with other bodies they does not get accelarate exactly towards each other(deviation along the path), it causes the dirrection of bodies to change. In this case the planets(cause of relatively small mass). 
If this deviation is large body(planet) fly by without any effect. If deviation is small, bigger body continuously change smaller one's direction, thus orbit.</p>

<p><a href="http://curious.astro.cornell.edu/about-us/57-our-solar-system/planets-and-dwarf-planets/orbits/243-why-do-the-planets-orbit-the-sun-beginner" rel="nofollow noreferrer">http://curious.astro.cornell.edu/about-us/57-our-solar-system/planets-and-dwarf-planets/orbits/243-why-do-the-planets-orbit-the-sun-beginner</a></p>

<p><a href="http://www.windows2universe.org/our_solar_system/formation.html" rel="nofollow noreferrer">http://www.windows2universe.org/our_solar_system/formation.html</a></p>

<p>fun Q:why does astronauts on ISS feel 0 gravity when ISS is revolving under earth's gravity? 
because they experience gravity but the revolution causes them to free fall, which they feel like 0 gravity.</p>

CC BY-SA 3.0
2016-11-27T07:08:09.547Z
2016-11-27T07:08:09.547Z
Sanket Deshpande
<p>Why do planets revolve around the sun? I understand that gravity plays a huge role in allowing it to move around. But what caused it to revolve in the first place? One possible solution is explained with the theory of relativity but is there a classical mechanics approach to this question? </p>

CC BY-SA 3.0
2016-11-28T03:39:58.753Z
Hi Sumedha - it couldn't be simpler.  The sun, planets started from a big cloud of gas.  *That cloud of gas was spinning* - so it's all still spinning.
Fattie
<gravity>
Revolution of Planets
Sumedha Biswas
# Revolution of Planets

(Asked by: username_0 on 2016-11-27)

Why do planets revolve around the sun? I understand that gravity plays a huge role in allowing it to move around. But what caused it to revolve in the first place? One possible solution is explained with the theory of relativity but is there a classical mechanics approach to this question?

**Tags:** gravity

> **Comments:**
> **username_1**: Hi username_0 - it couldn't be simpler.  The sun, planets started from a big cloud of gas.  *That cloud of gas was spinning* - so it's all still spinning.  

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## 1 answers

### Answer by username_2 on 2016-11-27. Score: 0

Classical mechanics approach to this would be **gravitational force** as we know `F=GMm/r2` and **Centripetal force** `F=mv2/r`.

In free space we when two things are kept some distance apart they accelarate towards each other (along straight line from center of on body to center of another body) due to force of gravity but if they are under some influence with other bodies they does not get accelarate exactly towards each other(deviation along the path), it causes the dirrection of bodies to change. In this case the planets(cause of relatively small mass).
If this deviation is large body(planet) fly by without any effect. If deviation is small, bigger body continuously change smaller one's direction, thus orbit.

<http://curious.astro.cornell.edu/about-us/57-our-solar-system/planets-and-dwarf-planets/orbits/243-why-do-the-planets-orbit-the-sun-beginner>

<http://www.windows2universe.org/our_solar_system/formation.html>

fun Q:why does astronauts on ISS feel 0 gravity when ISS is revolving under earth's gravity?
because they experience gravity but the revolution causes them to free fall, which they feel like 0 gravity.


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