So the door is hinged to the wall/floor by the leftmost hinge? and it folds up the way shown in the lower diagram? Then shouldn't the force be acting on the rightmost hinge instead? Also, what is the angle that the force is acting at?
(Dunno if this is a homework problem, or something else, but this is a terrible design for a trap door if you ask me. Why not go with the conventional single panel, release mechanism? )