Waiting for Manapua

Have you ever been to Island Manapua around lunchtime? It's packed! Their manapua are the best, and everyone knows it. Good for business, but bad for me because it results in my having to wait a long time in line before getting my lunch/snack, depending how early it is. Well, on Saturday, I found myself in this position, waiting in a long line to get my steamed pork manapua and rice cake. I was just inside the store and right up against the closed door. As I stood there, I began to get tired, so I decided to lean on the door. As I slowly leaned against the door and wondered whether it would swing open and send me falling backwards out the door, I realized "Hey! Static Friction! Torque! Physics!" It was an enlightening moment. There were forces al around me: my weight (mg down!), the friction of the floor on my shoes as well as the friction of the handle of the door (where I was leaning) on my back, keeping me from falling straight down. There were also the normal forces of the floor and handle on me. I have included an approximate Free Body Diagram above. But not only do these forces act on me, I am also applying a torque onto the handle bar, and thus to the door. The torque I applied would be equal to the normal force times the distance I was from the line of hinges on the edge of the door. There was even static friction between the hinges inside themselves, as well as static friction at the other sides of the door with the door posts. It was static friction and torque that allowed me to take a break by leaning on that door. The friction caused the door to stay in place, and my small distance from the hinges kept me from attaining so much torque that I would fall backwards out of the store. That would not have been fun. :-)