If an object doesn't accelerate, spin, or change direction, and assuming there are no external forces acting on it, it will indeed remain in a state of equilibrium. In this state, the object's velocity remains constant, and it continues to move in a straight line at a constant speed.
In classical mechanics, an object in motion tends to stay in motion with the same velocity unless acted upon by an external force, as described by Newton's first law of motion. This means that if the object is already moving with a certain velocity and there are no forces acting on it, it will maintain that velocity indefinitely.
However, it's important to note that in the real world, it is difficult to completely eliminate external forces. Factors such as air resistance, friction, and other environmental influences can affect the motion of objects. These forces can cause a change in velocity, even if the object is not accelerating or changing direction.
Additionally, the concept of "stationary" is relative. An object that appears stationary from one observer's perspective may be in motion relative to another observer. This is due to the principle of relativity, where motion is defined in relation to a frame of reference.
In summary, if an object doesn't experience any external forces, it will maintain its velocity and continue moving in a straight line at a constant speed. However, in the real world, various factors can influence an object's motion, and the concept of being "stationary" depends on the frame of reference.