Quickly must get it done for homework or into detention i go

how much is accomplished when two boys push a car a distance of 45 m with a force of 900 n? (give answer in joules)

a 53 kg student runs up a flight of stairs 5.5m high how much work (in joules) is done (you must first determine the weight of the student in newtons w=mxg)

a man applies a force of 60n in attempt to vove a desk 20m in spite of his effort, the desk refuses to budge how much work is accomplished