Torque(力矩) In the plane that is perpendicular to the axis,we define torque M as the cross product of the position vector and the normal component of the force respect to the axis 元=r×F z F r F  d Torque（力矩） In the plane that is perpendicular to the axis, we define torque as the cross product of the position vector and the normal component of the force respect to the axis   F r     M F