Knowing how to tie a variety of knots is a very practical skill a skill that save your life. The following are great resources for learning how to tie knots.
- http://www.youtube.com/user/AnimatedKnots – Bowline Knot
- http://www.animatedknots.com/bowline – Animated knots by Grog
I did not know that rope tying would be related to machines, until a rope typing expert told me this. He also recommended looking up “Archimedes ideal mechanical advantage.”
The following definition of machine is from http://www.encyclopedia.com/doc/1G2-3408600086.html:
“When the term machine is mentioned, most people think of complex items such as an automobile, but, in fact, a machine is any device that transmits or modifies force or torque for a specific purpose. Typically, a machine increases either the force of the person operating it—an aspect quantified in terms of mechanical advantage—or it changes the distance or direction across which that force can be operated. Even a humble screw is a machine; so too is a pulley, and so is one of the greatest machines ever invented: the wheel. Virtually all mechanical devices are variations on three basic machines: the lever, the inclined plane, and the hydraulic press. From these three, especially the first two, arose literally hundreds of machines that helped define history, and which still permeate daily life.”