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?
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).