If a nonzero net force is acting on an object, then the object's velocity is definitely changing. This is a direct consequence of Newton's Second Law of Motion, which states:

F = ma

Where:

* F is the net force acting on the object

* m is the mass of the object

* a is the acceleration of the object

Since the net force is nonzero, the acceleration must also be nonzero. Acceleration is the rate of change of velocity, so a nonzero acceleration means the velocity is changing.

Here are some important points to remember:

* Changing velocity can mean either changing speed or changing direction, or both.

* A nonzero net force does not necessarily mean the object is moving. The object could be at rest and the net force could be causing it to accelerate from rest.

* A constant velocity does not mean there are no forces acting on the object. There could be multiple forces acting on the object that balance each other out, resulting in a net force of zero and constant velocity.