Answer:
only when a nonzero net force is applied to the object.
Step-by-step explanation:
A net force is the sum of the unbalanced forces acting on an object. An object's motion changes only when a nonzero net force is applied to the object. When a nonzero net force is applied to an object, the object's speed and/or direction changes.
If the forces acting on the object are balanced, they will cancel each other out and will not cause the motion of the object to change.