Mechanical Advantage - IMA and AMA

A machine that looks identical on paper and in the real world will still give you two different answers, and mixing them up is the single most common way this topic gets missed on a test. Ideal mechanical advantage comes from geometry alone, a ruler could find it, no force measurement required. Actual mechanical advantage comes from what the machine really delivers once friction takes its cut, and it can only be found with a force reading. They're related, but they are never the same number, and efficiency is the gap between them made visible. Covered in this video: Ideal mechanical advantage, IMA = d-effort / d-load, and its specific forms for a ramp, a lever, and a pulley system Actual mechanical advantage, AMA = F-load / F-effort, built from real measured forces instead of geometry Why AMA is always smaller than IMA, and why an answer where AMA exceeds IMA means a formula got swapped Efficiency as the ratio of the two, and the direct link AMA = efficiency times IMA, used to work backward from a percentage to a force or a mass Counting rope segments to find a pulley's IMA, and the rule for what counts as a supporting strand versus the rope you're pulling on A side-by-side comparison table: what each advantage measures, what tool finds it, and which one friction actually touches This is core to Standard 4.1 (Energy Definitions and Calculations, including pulleys and mechanical advantage). The formulas are simple on their own. The test is whether you know which one a given problem is actually asking for. AUX — Free Physics Resources https://auxlearning.com