[[Work Energy and Power]]
megumi energy

# SUMMARY
* potential energy refers to multiple objects in a system affecting each other with conservative forces
* In MY words, potential energy is j stored kinetic energy that something has due to its surroundings, and it cashes it out and converts the PE to KE.
* Scalar
* You choose where potential energy is 0 to make a job easier
* Elastic potential energy of an ideal spring: $U_s=\frac{1}{2}k(\Delta x)^2$
* Gravitational potential energy between 2 spherical masses: $U_g=-G\frac{m_1m_2}{r}$. Near surface approximation: $\Delta U_g=mg\Delta y$
* For a system with more than 2 objects, potential energy is sum of energy of every pair.

## Zero Potential Energy Definition
* Can define zero PE as any convenient reference point
* For gravitational PE, a common ref point is ground level.
* Springs equilibrium is the natural zero PE point.