text: Centriptal Force\n\nAny motion in a curved path represents accelerated motion, and requires a force directed toward the center of curvature of the path. This force is called the centripetal force which means "center seeking" force. The force has the magnitude\n\nSwinging a mass on a string requires string tension, and the mass will travel off in a tangential straight line if the string breaks.\n\nThe centripetal acceleration can be derived for the case of circular motion since the curved path at any point can be extended to a circle.\n\nNote that the centripetal force is proportional to the square of the velocity, implying that a doubling of speed will require four times the centripetal force to keep the motion in a circle. If the centripetal force must be provided by friction alone on a curve, an increase in speed could lead to an unexpected skid if friction is insufficient.