No new force is added. The inward component of the net force causes centripetal acceleration.
This interactive 3D physics simulation explains circular motion without introducing a false extra force. The simulation shows that the inward component of the net force causes the centripetal acceleration.
For uniform circular motion, the speed is constant and the acceleration points toward the center of the circle. Therefore, the net force also points inward.
The phrase “centripetal force” should not be treated as a new force. It means the inward component of the net force. The real forces may be tension, friction, normal force, gravity, or a combination of forces.
In this simulation, a ball moves in a circle because the string pulls inward. The tension in the string provides the inward net force.
If the speed is changing, there is tangential acceleration. In that case, the total net force does not point exactly toward the center; it has both radial and tangential components.
The inward net force causes the inward acceleration in uniform circular motion.
In this example, tension is the real force that points inward.
Increasing speed increases the required inward force; increasing radius decreases it.
Do not add a separate “centripetal force” arrow unless it represents the net inward force.