Applying the laws of motion to circular motion
In uniform circular motion a body has centripetal acceleration a = υ²/R. By the second law this acceleration is produced by a force directed toward the centre: F = ma = mυ²/R = mω²R. This is the centripetal force. It is not a “new” kind of force but the resultant of real forces (tension, friction, gravity). For example, for a stone whirled on a string the tension is the centripetal force, and for a car in a bend the friction between wheels and road is. If the force disappears (the string breaks) the body flies off in a straight line along the tangent by inertia.
“Stone on a string”: only in imagination or video: if the string breaks, which way does the stone fly (along the tangent). Do not actually whirl anything. Safety: whirling an object on a string near people is forbidden.