In Dialog $6$ you found that the torque applied by a given force could be expressed one of two ways: in terms of the perpendicular distance or in terms of the straight$-$line distance and the angle at which the force is applied. With this in mind, what would be the torque provided by a force that was applied directly at the axis of rotation? What would be the torque provided by a force applied away from the axis but whose line of action passed through the axis? Explain your answers carefully.