The problem is a 2D one, regarded as seen from above (no gravitational forces are relevant). A pulley is attached to a cable and is pulled with the force "F" towards north. Through the pulley goes another cable and is firmly attached to the ground on one end and attached to a box with the mass "m". The cable is non-elastic and as the pulley is pulled towards north, the angle "theta" becomes larger. The two respective cable forces are "S1" on the firmly attached side, and "S2" on the side where the mass is being pulled.
The problem lies in trying to determine the x and y components of the cable force "S2", expressed by the force "F" and the angle "theta".
I am unsure how to start tackling this problem. I've had problems with pulleys before but never in this fashion where the pulley itself is being pulled. Can anyone shed a light on it for me so I can get started?