Work out wheel and axle instantly with clear inputs, formula shown and shareable results.
A wheel and axle is a rotating lever: the effort acts at the wheel radius and the load at the axle radius, so the mechanical advantage is their ratio. A 0.4 m wheel on a 0.05 m axle multiplies force eightfold, lifting 800 N with 100 N. Each full turn raises the load by the axle circumference, 0.314 m here.
Mechanical advantage
MA = wheel radius / axle radius
Lift per turn
lift = 2 pi x axle radius
Windlasses, well winches, capstans and car steering. A screwdriver handle is the same idea - a fat grip turning a thin shaft.
That is the trade-off. Eight times the force means one eighth of the travel, so a heavy load rises slowly.