Gravitational Potential Energy and just mgh, why are they different?

[chaser0]

GPE and mgh
Massive confusion

When we get further and further from earth, the GPE increases to ZERO. Meaning less energy that can be converted to KE. (which, means it actually is "decreasing" in E, but just from sign convention we say it is increasing?)

When we get higher for mgh, the E Increases to a higher positive number. Meaning More every that can be converted to KE.

So as you get further and further away from a planet, the Gravitational Force decreases and the GPE increases to zero.


So.... what exactly "is" gravitational potential E?"

I understand Gravitational Force (attractive force that decreases as you get further). I understand mgh (more E as you climb).
But... GPE.... is a value that increases as you climb, and leaves you with less E.
Could anyone help me to visualize this?

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[milski]

Negative numbers actually increase when they get closer to zero - the sign is not just "convention." In other words -100 < -50 - if an object had -100 J of energy, was moved up and now has -50 J of energy, its energy did increase by 50 J. You have the concept right - the gravitational potential energy increases as the object moves further way. The 0 place where the PE is 0 is very arbitrary - you could set the it to be at the surface of the planet/star or any other random distance. It's customary to set it to be zero at infinity, since that allows the PE from any distant start to be ignored in calculations. Since any object closer than infinity will have less PE, the PE ends up being a negative number.