If the net external force acting on the system of particles...

If the net external force acting on the system of particles is zero, then which of the following may vary?
(a) Momentum of the system
(b) Kinetic energy of the system
(c) Velocity of centre of mass
(d) Position of centre of mass

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Conservation of Linear Momentum

When the net external force acting on a system is zero, the total linear momentum of the system remains constant. This principle is a direct consequence of Newton's second law and holds true regardless of any changes in the system's internal configuration or energy distribution.

Kinetic Energy Variation through Internal Energy Changes

Even if external forces are absent, the kinetic energy of a system can change due to energy exchanges stemming from internal forces. Collisions, deformations, or other internal interactions might convert energy from one form to another, affecting the system's kinetic energy while leaving the total momentum unchanged.

Center of Mass Motion

In a system with zero net external force, the velocity of the center of mass remains constant because no external acceleration is applied. However, the position of the center of mass can still vary over time as it moves uniformly with this constant velocity.

Internal versus External Forces

Understanding the distinction between internal and external forces is critical in analyzing changes in a system. External forces influence the overall momentum and center-of-mass acceleration, whereas internal forces can alter the distribution of kinetic energy within the system without affecting its total momentum.

Transcript

Please give Ace some feedback