The Law of the Lever
Archimedes of Syracuse, Italy - was a mathematician and physicist at the time when Sicily was a Greek colony, who lived around the year 300 BC.
One of his many inventions and discoveries was that of the lever.
The famous saying: "give me a long enough leaver and I'll move the World", is often attributed to Archimedes.
We often say in Physics that the lever is a multiplier of strength.
Levers make use of the principle of the torque where a small input of force at one end is multiplied over a long radius of action and gives a large output of force at the other end of the lever.
The simplest lever is a first class lever.
Consider an ideal first class lever.
Ideal means that we don't take into account losses due to friction, heat, sound or other energy losses; and that the total energy-work of the sytem remains constant.
The law of the lever states that:
- Total Torque In = Total Torque Out
- Effort Torque = Load Torque
- Effort Force x Effort distance = Load Force x Load distance
In mathematical symbols Fe x de = Fl x dl
Activity: Verify the law of the lever for the first class lever in the images above.