Mechanical Comprehension Test (MCT)
The MCT tests qualitative physics, meaning you reason rather than compute. Core concepts: simple machines, with lever classes and mechanical advantage equal to effort arm divided by load arm; pulleys, where the advantage equals the number of rope strands supporting the movable block; inclined planes; wheel and axle; and gears, where two meshed gears rotate in opposite directions, gear ratio equals driven teeth divided by driver teeth, and an open belt keeps pulleys turning the same way while a crossed belt reverses them. Also know torque, center of gravity and stability, pressure as force over area, Pascal's principle in hydraulics, buoyancy, density, springs, series versus parallel circuits, Ohm's law, heat transfer, and basic kinematics, including velocity, acceleration, work, energy, and momentum.
Traps
Counting rope strands that do not support the load. Forgetting that mechanical advantage trades force for distance and never creates energy. Confusing mass with weight. Assuming a bigger gear turns faster; it turns slower with more torque. Ignoring the angle of a pull. Mixing up series and parallel behavior.
Rule of thumb and worked example
Mechanical advantage never creates work; force times distance stays constant. Worked example: a 10-foot lever has its fulcrum 2 feet from the load, leaving an effort arm of 8 feet. The advantage is 8 divided by 2, which is 4, so a 50-pound push can balance a 200-pound load (ignoring the lever's own weight and friction). When a question feels like a trick, ask which quantity is conserved.