Randall W(oodsman) R. of North Cuba, Florida posits this scenario: I’m entering a room and you’re exiting the room simultaneously through the same door. I’m pushing the door in as you are pulling on it. Who has the right-of-way?
You do, Randall. (And Definally. suspects that you knew that when you made yourself the one pushing the door, you crafty man.) You do, for two very scientific reasons:
1. Torque. It is much easier (that is, it requires less rotational force) for the one pulling on a door to hold the door open for the other person than it would be for the pusher to hold open the door. (This is because the puller is positioned at the end of the door farthest from the pivot, the hinge.) Indeed, to hold open a door after you’ve pushed it open, you pretty much need to be completely in the doorway—that is, in the way of the puller. So the puller should hold the door open for the pusher because it’s easier for the puller to do so.
2. Momentum. The pusher can push open a door and move through the doorway without breaking stride. The puller can not. The puller must come to a stop at the door to open it—in the process halting (if not actually reversing) his momentum.
Thus, physics dictates that the pusher goes through first. When he does, though, he had damned well better then hold the door open for the puller.