Undestand that Kinetic(max) = Dynamic(max)

[Hepic]

In physic,is true that energy of an object is the same.So we undestand that Kinetic(max)=Dynamic(max).
Why is that true?? There is any explanation with equations,or just only via observation?

 

[jfizzix]

That the total energy of a closed system of objects interacting with one another is constant is an empirical fact. However, we have good theoretical justifications for why the total energy ought to be constant.

The most amazing theory in physics that almost no one outside of the field has heard of is Emmy Noether's theorem.

What her theorem says is that

Because the laws of physics depend on only relative positions and not absolute positions, the total linear momentum is constant.

Because the laws of physics depend on only relative times and not absolute times, the total energy is constant.

Because the laws of physics depend on only relative orientation, and not absolute orientation, the total angular momentum is constant.There are other more exotic symmetries too leading to things like conservation of electric charge.