ABSTRACT
The fundamental importance of a force is that it is the cause of movement or change of movement in bodies. Thus, an aero plane in flight, a loom shuttle passing through the warp shed, action of knitting needle in knitting machine, the movement of the ring rail in spinning machines all have their movements as the result of action of their forces or the stopping of shuttle at the end of the traverse, or the change in the direction of a motor car turning a corner requires the application of force.
