When is Mechanical Energy Conserved?

Mechanical Energy (Kinetic + Potential Energy) is a very useful subset of energy in general. When energy is considered not conserved, very often it is just mechanical energy not being conserved.
We go through the steps you can take to understand if mechanical energy is conserved and then the equation you should build for yourself if it is and how to approach conservation of energy problems.
This video is intended for University Physics (Calculus-Based Physics) but is appropriate for College Physics, AP Physics, and High School Physics.