Centripetal refers to a force that acts on an object moving in a circular path, directing it toward the center of the circle. This force is essential for maintaining circular motion, preventing the object from flying off in a straight line due to inertia. Examples of centripetal force include the tension in a string when swinging a pendulum or the gravitational pull that keeps planets in orbit around the sun. In physics, centripetal acceleration is the rate of change of velocity of an object moving in a circle. It is calculated using the formula a_c = \fracv^2r , where v is the object's speed and r is the radius of the circular path. Understanding centripetal concepts is crucial in fields like engineering and astronomy, where circular motion is common.