A Definition of a Closed System

A system is just defined as a set of objects we are studying in a particular problem. A

In the real world, there are no true closed systems, unless you consider the universe to be a closed system. However, in physics we often loosen the definition of a closed system to mean a system with zero total outside force acting on it.

__closed system__is a system which has no external forces acting on it. In other words, if a system is closed, it is not interacting with anything which is located outside of the system.In the real world, there are no true closed systems, unless you consider the universe to be a closed system. However, in physics we often loosen the definition of a closed system to mean a system with zero total outside force acting on it.