Many handles are levers
A lever implements a way to increase an applied force by the ratio of the applied force arm length to the working arm length
The Lever Arm of the faucet increases the rotational force (torque) applied to the faucet to allow tight closure of the washer against the valve and control the water flow.
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First Class Levers
A see-saw is a good example of a first class lever. Another good example is a crowbar. The fulcrum is placed between the effort (Where a person pushes.) and the load (The heavy item they are trying to move.) The downward force at one end, with gravity on its side, allows the worker to use his full weight to push downward. The other end, with the heavy object, is then lifted against gravity.
Second Class Levers
A wheelbarrow is a good example of a second class lever. The fulcrum, the wheel, is at one end, the load is in the middle in the bin of the wheelbarrow, and the force is applied by the human at the handle end.
Third Class Levers
A hammer is an example of a third class lever. The fulcrum is on the top side of the handle at its end, and the human holds the hammer as close to the end as they can, applying the force. The load is the business end of the hammer that hits the nail.
More about Levers
A lever is simply a plank or ridged beam that is free to rotate on a pivot. It is perfect for lifting or moving heavy things. It is a very useful simple machine, and you can find them everywhere. Good examples of levers include the seesaw, crowbar, fishing-line, oars, wheelbarrows and the garden shovel.