The magnitude of the torque can be written using either the component of the force, \(F_\perp\) perpendicular to the vector \(\vec r\), or the lever arm, \(r_\perp\), of the force relative to the axis...The magnitude of the torque can be written using either the component of the force, \(F_\perp\) perpendicular to the vector \(\vec r\), or the lever arm, \(r_\perp\), of the force relative to the axis of rotation: \[\begin{aligned} \tau &= rF\sin\phi\\ &=rF_\perp\\ &=r_\perp F\end{aligned}\] where \(\phi\) is the angle between the vectors \(\vec r\) and \(\vec F\) when these are placed “tail to tail”.
