Hello!

When we cannot, say, lift a heavy load, we can apply a mechanism which reduces the force needed. Nothing comes free, and in this case we lose in speed. Sometimes, on the contrary, we want to win in speed (and have to lose in force).

A wheel and axle is one of the simple machines. It was founded several millenniums BC. Note that to obtain an advantage in force, a machine must be strong (firm) enough.

A mechanical advantage in force of a mechanism is defined as the ratio between the output force to the input force. For an ideal wheel and axle (with no energy dissipation) it is equal to the ratio between the radius of the wheel to the radius of the axle. In our case it is 3 (a dimensionless quantity).

The answer: the ideal mechanical advantage of this machine is 3.