e.g. pushing a door with x-lbs of resistance, assuming a person is exerting force perpendicular to the door, 36" from hinge. What is that x-lbs (max) an average adult could pushing with ease?
I like this solution. Sometimes experiment is the way to go. Theory can help you only so much because of all the assumptions that one has to make to approximate any real world situation. =]Why don't you find a spring-type bathroom scale, hold it up against a wall, and push. What does the scale read? There's your answer (if you are 'average,' whatever that means).