Potential Energy and gravitation

[shounakbhatta]

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

 

[russ_watters]

Upper-case G is the universal gravitational constant. It is basically just a conversion factor. It is negative by convention.

 

[shounakbhatta]

Hello,

What is the conversion factor?

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

-- Shounak

 

[tiny-tim]

Hello Shounak!

This thread is similar to your other thread, https://www.physicsforums.com/showthread.php?t=662573

Is there anything here that has not yet been answered there?