As we have seen from our discussion of rotational motion, torque is the rotational analogue of force in the same way the moment of inertia is that rotational analogue of mass.  But what is a torque?  Mathematically, torque is the moment of the force vector.  (In fact, in some engineering classes, the term “moment” is preferred over “torque” to refer to the same concept.)  In the same way that the moment of inertia cares about not just the mass, but also how it is distributed relative to an axis, the torque doesn’t just care about the force acting on an extended object.  It also cares about where that force acts relative to an axis of rotation.  As we will see, when a force acts on an object to create a torque about an axis, the torque acts to try and make the object rotate about the axis in a particular direction.