Newton's First Law
Stop! It's inertia
Newtons First Law: An object at rest will remain at rest, and an object in motion will remain in motion at a constant velocity unless an unbalanced force acts upon it.
Inertia: Any resistance of any physical object to any change in its state of motion including changes to its speed and direction or the state of rest. It's the tendency of objects to keep moving in a straight line at a constant velocity.