Final answer:
In physics, a system is defined by the boundaries of an object or a group of objects. Forces originating outside the system are external forces which affect the system's motion according to Newton's laws.
Step-by-step explanation:
The concept in question refers to a system as defined in physics. A system is a specified collection of objects or an individual object chosen for analysis. When considering the forces acting upon this system, forces originating from outside of the system's boundaries are identified as external forces.
Understanding these forces is crucial for applying Newton's laws of motion, as these laws dictate that only external forces affect the motion of the system. Internal forces, on the other hand, are the forces that act between elements within the system, and they typically cancel each other out when considering the system's motion.
An important aspect of studying force in physics is the ability to determine the boundaries of a system to identify which forces are internal and external. This is a foundational concept in physics essential for understanding how interactions, such as forces and the transfer of quantities, can result in changes to the system's state in accordance with conservation laws. The application of a free-body diagram can also be instrumental in visualizing and calculating the net force acting on a system.
The complete question is: The identified object or collection of objects that will interact and the thing upon which external forces acts is: