Which of Newton's laws states that an object with no net force will remain in rest or in constant velocity?
Newton's first law states that an object at rest will remain at rest, and an object in motion will remain in motion in a straight line unless acted upon by an unbalanced force.
This is also called the law of inertia, which is the resistance to a change in motion. Whether an object is at rest or in motion in a straight line, it has constant velocity.
Any change in motion, whether it be amount of speed or direction, is called acceleration.