Wheel and Axle

The wheel and axle mechanism is not just a simple free turning wheel such as:

The front wheel of a typical bicycle

Instead, this type of machine uses:

Two wheels mounted on a shaft, with one wheel having a larger diameter than the other

The large diameter wheel will:

Usually be the one that has the effort applied to it

Large movements of the large wheel result:

In small movements of the small wheel

The larger wheel has a greater circumference, so:

A point on the edge of it travels further per turn compared to a point on the smaller wheel

Since a large movement(or distance) is being translated into a small movement:

The force is then being increased

The amount of mechanical advantage is determined by:

The ratio of the diameter of the wheels

If the large wheel is 20 inches in diameter, and the small wheel is 10 inches in diameter:

The total mechanical advantage is 2:1