Boiling water is water that's bubbling at 212ºF. ... Simmering, on the other hand, is slower than that nice bubbling boil. It's still very hot—195 to 211ºF—but the water in this state isn't moving as quickly and isn't producing as much steam from evaporation. Simmering water is great for soups, broths and stews.
An example of a first class lever in the human body is the head and neck during neck extension. The fulcrum (atlanto-occipital joint) is in between the load (front of the skull) and the effort (neck extensor muscles). The muscles are attached to the posterior part of the skull to allow for the greatest effort arm.