Relationship between centripetal force and gravitational force of satelite

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Discussion Overview

The discussion revolves around the relationship between centripetal force and gravitational force in the context of a satellite's orbit around the Earth. It explores the conditions necessary for a stable circular orbit and the role of gravitational force in providing the required centripetal acceleration.

Discussion Character

  • Conceptual clarification
  • Technical explanation
  • Exploratory

Main Points Raised

  • One participant states that for a satellite to maintain an orbit, the centripetal force must equal the gravitational force acting on it.
  • Another participant clarifies that centripetal acceleration is necessary for curved motion and that gravity provides this acceleration for satellites, suggesting that they are effectively the same in this context.
  • A participant questions what would happen if gravitational force were to increase or decrease significantly while a satellite is in orbit.
  • There is a suggestion that the centripetal acceleration of a satellite in orbit is equivalent to the gravitational acceleration exerted by the planet it orbits.
  • One participant emphasizes that gravity is the only force acting on the satellite, implying that no other forces contribute to its motion in orbit.

Areas of Agreement / Disagreement

Participants generally agree on the role of gravity in providing the necessary centripetal acceleration for a stable orbit, but there are nuances in how this relationship is articulated. The discussion does not reach a consensus on the implications of changes in gravitational force.

Contextual Notes

Some assumptions about the conditions for stable orbits and the effects of external forces (like thrusters) are mentioned but not fully explored. The discussion also does not resolve the implications of varying gravitational forces on orbital stability.

Tommy1995
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In order for a satelite to achieve an orbit around the Earth the centripetal force of it needs to be exactly the same as the force of gravitation which is acting upon the satelite. Why is this so?
 
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The question is slightly badly worded.

An acceleration occurs when there is a change of velocity. Velocity has components speed and direction and to change either component you need an acceleration. Centripetal acceleration is the name given to an acceleration that causes an object to move in a curved path.

In the case of a satelite gravity provids the centripetal acceleration. So gravity is allways "the same" as the centripetal acceleration (except perhaps when thrusters are being fired but let's ignore that).

So what I think you are really asking is this... What centripetal acceleration is required for a stable circular orbit and what happens if it's more or less than that value?

The centripetal acceleration required for uniform circular motion is given by v2/r. That equation is derived here..

http://www.gb.nrao.edu/~rmaddale/Education/Wvsta'98/Centripetal.html
or
http://dev.physicslab.org/Document....me=CircularMotion_CentripetalAcceleration.xml

So for a stable circular orbit gravity must provide exactly that acceleration. If it was more or less than that value the path wouldn't be circular.

Imagine you have got your satelite into a nice stable circular orbit, what happens if gravity were to suddenly increase dramatically or dissapear?
 
CWatters said:
Centripetal acceleration is the name given to an acceleration that causes an object to move in a curved path.

In the case of a satelite gravity provids the centripetal acceleration. So gravity is allways "the same" as the centripetal acceleration (except perhaps when thrusters are being fired but let's ignore that).

So for a stable circular orbit gravity must provide exactly that acceleration. If it was more or less than that value the path wouldn't be circular.

I can nicely see where your getting at CWatters! I was wondering if this might mean mean that the centripetal acceleration of a satelite traveling in its orbit would be the same as the gravitational acceleration provided by the planet it is orbiting?
 
Where else do you think it could come from? Gravity is the only force acting on the satellite, isn't it?
 
Thanks so much guys ! I finally understand this ! :d
 

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