What is the relationship between momentum conservation and external impulses?

What is the relationship between momentum conservation and external impulses?

• A. Momentum is conserved only in the absence of external impulses.
• B. Momentum cannot be conserved in any real system.
• C. Momentum is always constant regardless of external forces.
• D. In a closed system with no external impulses, total momentum is conserved.

Answer: (D)

Momentum conservation happens when the total external impulse on a system is zero. An impulse is the effect of external forces acting over time, so if external pushes cancel out or there are no external forces at all, the system’s total momentum stays the same. Within a closed or isolated system, internal interactions can swap momentum among parts, but they don’t change the overall momentum because those forces are internal. The statement that matches this idea is that in a closed system with no external impulses, total momentum is conserved. External impulses can change momentum, so momentum isn’t necessarily constant if there are net external forces present.

Momentum conservation happens when the total external impulse on a system is zero. An impulse is the effect of external forces acting over time, so if external pushes cancel out or there are no external forces at all, the system’s total momentum stays the same. Within a closed or isolated system, internal interactions can swap momentum among parts, but they don’t change the overall momentum because those forces are internal. The statement that matches this idea is that in a closed system with no external impulses, total momentum is conserved. External impulses can change momentum, so momentum isn’t necessarily constant if there are net external forces present.