A pull up door is stuck in the closed position. A strap, fastened on the inside bottom and located at the center of the door is pulled outward at an angle of 45 deg above horizontal in attempt to raise it. A rubber door seal is on the bottom of the door and the strap passes under that seal so that the force is outward. The coef. of friction measures .52 between the seal and the strap. How much does the friction force detract from the force the strap feels at its fastener?