I am a high school student. I am having confusions about the centripetal force and rotational motion.
I have known that a body will be in rest or in uniform velocity if any force is not applied. But a force will be needed to create a rotational motion in a body. That force is called the centripetal force and it acts vertically with the direction of linear velocity of the body in rotational motion.
My question is, how an object (e.g. stone) attached with a rope rotates by the force we apply by our hand to the system (rope and the stone) while holding the other end of the rope? Though I have made an answer I am not satisfied with it.
When we attach a rope with a stone and hold the other end with our hand and we rotate our hand and create a rotational force to rotate the system , the vector (axial vector) of the rotational force by our hand acts vertically with the plane of rotation of our hand and acts through the rope. This force which acts through the rope and through the axial vector of the rotating force created by our hand acts as the centripetal force to the stone. Another force which is same and opposite to this centripetal force is the centrifugal force which is a pseudo force and acts through the rope and straightly outside the system.
The direction of centripetal force is towards the centre of rotation through the rope and that of centrifugal force is towards the object through the rope. This centrifugal force tries to get the stone out of the rotating circle through the vector of the rope stretched outside. But due to the tension of the rope and centripetal force, the object cannot get out. Due to the tension and centripetal and centrifugal force, the rope and the stone together acts as ONE tough system (like a single stick) and as we rotate a stick and as we rotate our hand the stick rotates, likewise the system also rotates.
But this explanation is not satisfying because I can't get how it is rotating? I mean, the centrifugal and centripetal forces are just maintaining the system to be rigid and stable but what is the force that is helping the stone and the rope to rotate? How does that force work? Is that force (which helps the system to rotate) centripetal? Or the rotating force applied by our hand?