The principle of the lever

Give me a lever and I will lift the world

Various parts of the human body, as well as many everyday objects, are operated by levers.  It seems like a common mechanism, nothing special, but the principle of the lever has not always been known, let alone employed by human beings.

In antiquity, only human effort was used to perform any work.

In the 3rd century BC. Archimedes, one of the greatest mathematicians of all time, was the first to address the principle of leverage in his treatise On the Equilibrium of Planes. Archimedes established that the ratio between the arms of resistance and power is inversely proportional to the ratio between the forces, the more one increases the more the other decreases.

A lever (a rigid object), can rotate around a fulcrum (a rigid fixed point); at the extremes of the lever, on the arms (distance from the fulcrum), 2 forces act: resistance (which must be overcome) and power (which is applied). If the power is applied at a greater distance from the fulcrum (longer arm) than the distance of the resistance (shorter arm), there is an advantage; otherwise not: the resistance will have a longer arm and more power will be required to overcome it.

In the human body, the power is always provided by a muscle, the resistance by the weight of the part we have to move, the fulcrum being the joint of the two bones.

The famous phrase 'Give me a lever and I will lift the world' is attributed to Archimedes. The mathematician's studies on the principle of the lever were fundamental. Once the fulcrum and the weight of the body have been identified, it is indeed possible to lift any weight with a very small force.

The formula for calculating a lever is: power X arm of power = resistance X arm of resistance.

Design of Feda Manhole Cover Lifter exploits the basic principle of Archimedes. The lever, in combination with the coupling system on the manhole (which represents the weight to be lifted), allows the power to be applied at a greater distance from the fulcrum than the distance of the resistance.