Mechanical Abilities · Study Guide
Mechanical Reasoning: Simple Machines
We teach how simple machines work: gears, pulleys, levers, and more. Many locals use a short timed set with diagrams. Locals vary. Check your local's test format. Learn the core principles and you can reason through any variation.
1. Gears
Meshing gears turn opposite directions. The ratio is teeth on the driven gear divided by teeth on the driver. More teeth means slower rotation and more torque.
Example
A 20-tooth driver at 60 RPM meshes with a 40-tooth driven gear. How fast does the driven gear turn?
Ratio: 40 ÷ 20 = 2. The driven gear has twice the teeth, so it turns at half the speed.
Answer: 30 RPM, opposite the driver.
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Gears have their own guide
Direction rule, torque trade-off, animated demo, and more worked examples: all free, no signup.
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