If a torque is applied to the disk in like this a fashion those the axis of the torque is the alike as those of rotation of the disk, the direction of the former will be parallel to AB.

• 假如力矩是那样地功能于一圆盘上，即力矩的轴与圆盘的旋转轴方向一致，则力矩的方向与AB线平行。