I know what the definition of torque and angular momentum is. But I read in a few books that "Torque and angular momentum are not independent laws of nature, and have been derived from the more fundamental laws of newton." The above simply means, that the rotational motion is just a manifestation of newton's laws at work. How can we "derive" the concepts of torque and angular momentum by using just the newton's three laws? Another way to look at the problem: Suppose we have an extended body, say a rod. Now I apply a force F at some point of this rod, apart from the center of mass. Let the rod's net mass be M. All the points on the rod, will then have an acceleration component in the direction of the force F, given by a=F/M. But apart from this acc. component, all the points, except the C.O.M. have another additional component of acceleration, that is the angular acceleration. My question is, Where did this angular acc. component come from? what caused it? (please don't give a lame answer like "torque of F caused it") Please give your answer by using only newton's laws and not torque or angular momentum. According to the newton's second law, the force F produces acc. a=F/M in all the points lying on the rod. But all the points(except c.o.m.) almost magically acquire another acc. component, i.e. the angular acc. Please explain, how the newton's laws, give rise to this extra angular acc. component.