2.1 LEVERS

A lever is a rigid bar that urns around a point called FULCRUM. Various forces may act on the lever at the same time.

Each force produces a specific torque.

                                           TORQUE = FORCE X DISTANCE 

Clases of levers

We can divide levers into three classes according with the position of the fulcrum, the force and the resistance.

Class 1:

The fulcrum is between the force and the resistance.

Class 2:

The resistance is between the fulcrum and the force.

Class 3:

The force is between the fulcrum and the ressistance.

Brake levers

We control bicycle levers to reduce speed, with levers on the handlebars.

A hand crack

A hand crack has two parts. One is conected to a rotating shaft and the other forms a handle. We can use it to apply force at a distance from the axis of the shaft.

Bicycle handlebars

The handlebrs of a bicycle work like a crank. If we place our hands at the ends of the handlebars, they are easier to turn.