I need to calculate the torque needed to move an object in horizontal direction. The object is subjected to a force P also in horizontal direction. The general situation is as follows: a (hor.) lever is connected to a (vert.) shaft which will provide the torque. The other end of the lever is connected*to the object. Now, my problem lies in understanding the torque needed to move the object for different types of connection between lever and object. There are 3 situations: connection is a hinge* or there is no fixed connection but the lever can slide against the surface of the object with a high* friction coefficient or very low* coefficient. So, apart from the force P applied to the object, the lever also has to overcome the force due to friction with the object surface or the force on the hinge.