Net external force

Definition

Net external force is the vector sum of all the forces acting on a system from outside the system. It determines the acceleration of the system according to Newton's Second Law of Motion.

5 Must Know Facts For Your Next Test

1. Net external force is zero when a system is in equilibrium, meaning there is no acceleration.
2. According to Newton's Second Law, net external force equals mass times acceleration ($F_{net} = ma$).
3. Only external forces affect the motion of a system; internal forces cancel out and do not change the system's overall motion.
4. The direction of the net external force determines the direction of the acceleration.
5. Free-body diagrams help visualize and calculate net external forces acting on a system.

Review Questions

Related terms

Newton's Second Law of Motion: States that the acceleration of an object is directly proportional to the net external force acting on it and inversely proportional to its mass ($a = \frac{F_{net}}{m}$).

Equilibrium:

A state where all forces acting on a system are balanced, resulting in no acceleration.

Free-body diagram: A graphical representation used to visualize all external forces acting on a single object or system.