transamz9 wrote:
:S
Here it is as simply as it can be put.
http://en.wikipedia.org/wiki/Torque
If you push on the door panel, that is a force. It is not torque. If you push or pull on a torque wrench, you are putting a force on the wrench which puts a rotational force (torque) on the nut and turns it on the bolt. The measureable torque is producing work. The hinges on a door or the axle on a revolving door are not producing rotational work. The are supporting the weight of the door and if there is any measureable resistance to rotation, they need some lubrication. Don't confuse kinetic energy with torque. Unless the hinges or axle are producing rotational force (torque) to cause their movement, it's not torque that opens or rotates the door. It's linear force as the person "pushes" the door open. The hinges or axle are idle support for the weight of the door.
