What is an unbalanced force?

An unbalanced force is a net force that causes a change in an object's motion.

• Definition: An unbalanced force occurs when the sum of all forces acting on an object is not zero. This means there is a net force that causes acceleration. Learn more about forces.

• Effect: Unbalanced forces cause an object to accelerate, meaning it changes its velocity (speed and/or direction). This is directly described by Newton's Second Law of Motion.

• Examples:

  • A car accelerating from a standstill has an unbalanced force acting on it from the engine.
  • A ball falling due to gravity experiences an unbalanced force.
  • Pushing a box across the floor where your applied force is greater than the friction force.

• Comparison to Balanced Forces: In contrast to unbalanced forces, balanced forces result in no change in motion; the object remains at rest or continues moving at a constant velocity.