Confusion over potential energy equation.

AI Thread Summary
The potential energy equation MGH is an approximation valid near the Earth's surface, where M is mass, G is gravitational acceleration, and H is height. The alternative equation, GmM/r, is more accurate for gravitational potential energy at varying distances but is less commonly used due to its complexity. The confusion arises from the difference in context, as "height" is not as straightforward when considering distances from spherical bodies. Additionally, the correct form of the gravitational force equation does not involve squaring the distance. Understanding these distinctions clarifies the application of each equation in different scenarios.
Kyle Barr
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Hi, I am confused over the potential energy equation. I have been taught that potential energy is MGH M=mass, G=gravity on surface, and H=height from earth. However being on the internet and learning more i have noticed people use GmM/r^2 and i am very confused why it is switched. please help me with my confusion? Thank you. (:
 
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Welcome to PF,
the equation for gravitational potential energy you learned is an approximation that holds close to the surface of the Earth. The other one is more correct in general, though there should be no square on the bottom, but is a pain to use, so we only use it when we have to.
Consider... the word "height" does not make much sense for the distance from a sphere.
 
thank you very much! and i just realized it is + distance, not squared. i got confused with the force of gravity equation.
 

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