Potential Energy and gravitation

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Discussion Overview

The discussion revolves around the concepts of gravitational potential energy and the gravitational force, specifically focusing on the role of the gravitational constant (G) in various equations related to gravitation. Participants seek clarification on how G appears in different contexts, including potential energy and gravitational acceleration.

Discussion Character

  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Shounak asks for an explanation of the equation F=G m1m2/R^2 and its relation to potential energy U=mgh, specifically how -G appears in the potential energy equation U=-Gxm1xM2/r+K.
  • Shounak inquires about the meaning of the universal gravitational constant G and why it is negative in certain equations.
  • Another participant notes that G is a conversion factor and mentions that it is negative by convention.
  • Shounak seeks clarification on whether the equations for G and -G are equivalent.
  • A participant references a previous thread, suggesting that similar questions may have been addressed there.

Areas of Agreement / Disagreement

The discussion remains unresolved, with participants expressing different levels of understanding regarding the role of G in gravitational equations. There is no consensus on the specific nature of the conversion factor or the implications of the negative sign.

Contextual Notes

Participants have not fully defined the conversion factor or clarified the assumptions behind the use of -G in the equations discussed. The relationship between the equations remains ambiguous.

shounakbhatta
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Hello,

Can someone please explain me:

F=G m1xm2/R^2

In potential energy U=mgh

Generally it is also written that:

U=-Gxm1xM2/r+K. How -G comes into play?

Also Newton's above law of Gravitation in vector form is written as:

F_12=-Gm1m2/r12^2 r12

Here also how -G comes into play?

Coming to Gravitation acceleration:
If one of the masses is larger than the other, gravitational field is defines as:

g=-GM/r^2xr_hat

How again -G comes into play?

If somebody can explain in a step by step method....


Thanks,

-- Shounak
 
Physics news on Phys.org
Upper-case G is the universal gravitational constant. It is basically just a conversion factor. It is negative by convention.
 
Hello,

What is the conversion factor?

Does that mean the equation for G and -G are the same?

-- Shounak
 

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