Descrição
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Potential energies are only associated with conservative forces. The change in potential energy between two configurations of a system is the negative of the work done by the conservative force during the change. Because the gravitational field near the surface of a planet is nearly constant, the change in gravitational potential energy of a system containing an object and a planet when the object is near the surface of the planet can be approximated by ΔU_g = mgΔy.
Sections:
00:00 - Intro
00:26 - Calculating work done by gravity
05:00 - Why is gravity a conservative force?
06:19 - Why is friction a nonconservative force?
09:09 - Defining potential energy for conservative forces
12:18 - Conservation of mechanical energy
14:03 - General equation for potential energy change
16:28 - Summary
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