Centripetal acceleration is the acceleration experienced by an object moving in a circular path. It is directed towards the center of the circle and is responsible for changing the direction of the object's velocity, keeping it in circular motion. The formula for centripetal acceleration is a_c = \fracv^2r , where v is the object's speed and r is the radius of the circular path. This type of acceleration occurs in various scenarios, such as a car turning around a curve or a planet orbiting a star. Without centripetal acceleration, these objects would move in a straight line instead of following a curved path.