A
lever (
/ˈliːvər/ or
US:
/ˈlɛvər/) is a
simple machine consisting of a
beam or rigid rod pivoted at a fixed
hinge, or
fulcrum. A lever is a rigid body capable of rotating on a point on itself. On the basis of the location of fulcrum, load and effort, the lever is divided into
three types. It is one of the six
simple machines identified by Renaissance scientists. A lever amplifies an input force to provide a greater output force, which is said to provide
leverage. The ratio of the output force to the input force is the
mechanical advantage of the lever.
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....Class 2: Resistance (or load) in the middle: the effort is applied on one side of the resistance and the fulcrum is located on the other side, e.g. in a
wheelbarrow, a
nutcracker, a
bottle opener or the
brake pedal of a car, the load arm is smaller than the effort arm, and the mechanical advantage is always greater than one. It is also called force multiplier lever.