Work and Energy - Mission WE7 Detailed Help

If the only forces doing work upon an object are conservative (or internal) forces, then the total mechanical energy of the object will ____. If the only forces doing work upon an object are non-conservative (or external) forces, then the total mechanical energy of the object will ____.


 
Definition of Conservative Force:
All the different types of forces that could do work upon an object can be categorized as either conservative or non-conservative forces. A conservative force is a type of force that serves to transform an object's energy between kinetic and potential. When only conservative forces do work upon an object, the energy of the object changes forms (KE to PE or vice versa) without changing the total amount of mechanical energy.


 
Definition of Non-conservative Force:
All the different types of forces that could do work upon an object can be categorized as either conservative or non-conservative forces. A non-conservative force is a type of force that changes the total amount of mechanical energy possessed by an object. When non-conservative forces do work upon an object, the total amount of mechanical energy changes.