In any system, the net sum of energy coming out of a situation will be the same as it was when the system started. This is the Law of Conservation of Energy. The universe has a finite amount of energy; it cannot be created or destroyed, just transformed from one form to another. This leads to a rather sobering fact: no matter what, no more energy (or matter) can ever be truly created.
Conservation of Energy has important uses in physics. It is often used in equations to find the resident pieces of the kinetic and potential energy equations. More importantly, it has shown that objects can have both kinetic and potential energies during their movement, except at rest or at the peak of their motion.
Quantitatively, Conservation of Energy is very simple:
Another, more useful, way of expressing Conversation of Energy quantitatively to express potential energy as equal to kinetic energy:
Of course, there can be more than one potential and kinetic value in the equation given the situation.
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