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
Messages
2
Reaction score
1
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. (:
 
  • Like
Likes Greg Bernhardt
Physics news on Phys.org
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.
 
Thread 'Is 'Velocity of Transport' a Recognized Term in English Mechanics Literature?'

Thread 'Is 'Velocity of Transport' a Recognized Term in English Mechanics Literature?'

Here are two fragments from Banach's monograph in Mechanics I have never seen the term <<velocity of transport>> in English texts. Actually I have never seen this term being named somehow in English. This term has a name in Russian books. I looked through the original Banach's text in Polish and there is a Polish name for this term. It is a little bit surprising that the Polish name differs from the Russian one and also differs from this English translation. My question is: Is there...
View full post »

Thread 'Is calling fictitious forces "not real" just about terminology?'

Hi there, im studying nanoscience at the university in Basel. Today I looked at the topic of intertial and non-inertial reference frames and the existence of fictitious forces. I understand that you call forces real in physics if they appear in interplay. Meaning that a force is real when there is the "actio" partner to the "reactio" partner. If this condition is not satisfied the force is not real. I also understand that if you specifically look at non-inertial reference frames you can...
View full post »

Similar threads

I Change of coordinates in a potential energy field
Replies
2
Views
1K
Question about potential energy: gravity and a vertical spring
Replies
12
Views
4K
I How to interpret this definition of potential energy?
Replies
10
Views
2K
Confused about some basic mechanics principles (force , PE)
Replies
6
Views
1K
Regarding the idea of potential energy
Replies
2
Views
1K
Gravitational potential energy question -- Ojbect sitting on the Earth
Replies
3
Views
1K
Two separate "gravitational potential energy" equations?
Replies
11
Views
3K
How to relate the gravitational potential energy zero to the axes?
Replies
4
Views
2K
Does Increasing Potential Energy Affect the Gravitational Pull on an Object?
Replies
16
Views
1K
B Work and energy: conceptual doubt
Replies
2
Views
2K

Hot Threads

Recent Insights

Back
Top