Mechanical Advantage

A simple machine never gives something for nothing: it trades force for distance. Pick a lever, pulley or ramp and watch the load rise 1 metre while the effort travels the distance the geometry demands. The readouts expose the deal — a bigger mechanical advantage means less effort, but over a longer path, and friction (efficiency) always takes its cut.

Mechanical advantage IMA

4.00

actual AMA = eff × IMA = 3.20

Effort force F_e = F_load ÷ AMA

156 N

lifts the 500 N load

Effort distance d_e = IMA · d_load

4.00 m

while the load rises 1.00 m

Work in & out W_out ÷ W_in = eff

625 J in · 500 J out

efficiency = 80%

Load force500 N

Efficiency80%

Lever · effort arm1.00 m

Lever · load arm0.25 m

Reference lift d_load = 1.00 m · g = 9.81 m/s² · IMA kept at 1 or more

Watch the trade: raise the effort arm (or add rope segments) and the effort force drops — but the effort distance grows by the same factor. W_out/W_in stays pinned at the efficiency.