When a top is spinning, it wont fall down to the land as long as its angular speed is large. I can understand this phenomena from the Torque-Angular momemtum perspective. Howevr, i can understand it from F=ma 's perspective. Sine its center of mass is making a circular motion around the Z-axis (not its symmetrical axis!) , there must be a centripetal force to act on it. Where does the centripetal force comes from? I am not sure whether i am right..... What i also understand is : The normal force acting on the top must be equal to the weight of the top...since the centre of mass doesnt fall down Can anyone explain the motion of the top's centre of mass? Where does the centripetal force comes from??ho Thanks!