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Isolated vs Non-Isolated Systems
Unit: Linear Momentum
Later Topics
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A system is a specific collection of objects contained within a conceptual boundary. We classify systems based on the origin of the forces acting on the objects in the system relative to this boundary.
Internal forces act between objects present inside the system. According to Newton's Third Law, these forces exist in equal and opposite pairs. Therefore, by definition, the net internal force is always zero:
External forces are exerted on objects within the system boundary by sources outside the boundary. Net external forces can be non-zero.
... continued in the full lesson.
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