Simple Machine Efficiency

Compare pulley systems, inclined planes, and levers through force, work, friction losses, and efficiency.

Active Machine

Pulley System

Force Comparison

Work and Loss Flow

Efficiency Comparison

Pulley System 0%

Ideal: 0 N

Actual: 0 N

Inclined Plane 0%

Ideal: 0 N

Actual: 0 N

Lever 0%

Ideal: 0 N

Actual: 0 N

Current Formulas

Mechanical Advantage MA = 2n
Ideal Force F_ideal = mg / (2n)
Actual Force F_actual = F_ideal + μmg / n
Work W_input = F_actual × d_input
Efficiency η = W_useful / W_input

Ideal vs Real Machines

Simple machines do not create energy. They trade force for distance. In the ideal case the input work exactly equals the useful output work, but real systems need extra work to overcome friction.

Why Friction Matters

Bearings, surface contact, and pivot resistance all convert part of the input work into heat. That loss raises the actual force above the ideal prediction and lowers the machine efficiency.

Energy Accounting

Efficiency is computed as useful work divided by total input work. The difference between those two bars is the energy lost to friction, deformation, and internal resistance.

Applications

Cranes use pulley systems, ramps use inclined planes, and pry bars use levers. Comparing them side by side helps explain when high mechanical advantage is worth the added travel distance and losses.