Uniform circular motion: When a body moves in a circular path with uniform speed (constant speed), its motion is called uniform circular motion.When a body moves in a circle, its direction changes continuously. Due to this change in direction we say that velocity changes and the motion is accelerated. From Newton’s 1^st law we know that to create acceleration an external force is required. Hence we need a force to keep the body moving in a circular path.This force is called Centripetal Force.