In space, an object has only ONE force acting on it. Can the object have constant acceleration and/or a velocity of 0. Explain.

yes, it can have constant acceleration and at one time, zero velocity. Consider the direction of the acceleration. What happens when you put on the brakes of a car?

In space, an object can have only one force acting on it and still have constant acceleration and/or a velocity of 0. This is possible due to Newton's second law of motion, which states that the acceleration of an object is directly proportional to the net force applied on it and inversely proportional to its mass.

If the object is experiencing a single force that is not balanced by any other forces, it will accelerate in the direction of that force. If the force is applied in such a way that the object's mass cancels out the effect of the force, the object will have constant acceleration. The acceleration will remain the same as long as the net force acting on it remains constant.

On the other hand, an object can have a velocity of 0 even if it has a non-zero constant acceleration. This occurs when the object's acceleration is applied in the opposite direction of its initial velocity, causing it to slow down and eventually come to a stop. Despite having zero velocity, the object can maintain a constant acceleration due to the continuing net force acting on it.

To summarize, in space, an object can have only one force acting on it and still have constant acceleration and/or a velocity of 0. The specific conditions for this depend on the magnitude and direction of the force in relation to the object's mass and initial velocity.