Practice Mechanical Reasoning Test

What is mechanical reasoning?

Mechanical reasoning is the ability to understand how physical systems such as levers, gears, pulleys and springs behave, and to predict what happens when a force is applied.

Tests use simple diagrams and everyday physics rather than equations. Research by Mary Hegarty suggests people solve them by mentally animating the machine one part at a time, which is why tracing the chain step by step beats guessing from the overall picture.

By What's Your IQ · Published 4 Oct 2026 · Updated 4 Oct 2026

Format: A diagram or scenario plus 3–4 options
Topics: Levers, gears, pulleys, ramps, hydraulics, springs
Used for: Engineering, trades, military and technical roles
Measures: Physical intuition, mental simulation, spatial tracking
This test: 10 questions, 10 minutes, free, explained answers

Six systems, six rules

Learn the one-line rule for each. Almost every question is one of these in disguise.

Leverforce × distance = force × distanceFurther from the pivot, less force needed. A longer spanner or crowbar works the same way.

Gearsmeshed gears reverse direction; turns × teeth stay equalA small gear driving a big one turns slower but with more force.

Pulleyseffort ≈ load ÷ supporting strandsCount the rope strands holding the moving pulley, not the pulleys.

Rampslonger slope → less force, more distanceLifting the same height always takes the same work.

Hydraulicspressure is equal everywhere in the fluidForce grows with piston area; travel shrinks by the same factor.

Springsstretch ∝ force; side by side halves it, end to end doubles itHooke's law: double the weight, double the stretch.

Gear lab

Change the chain. Directions alternate, and only the first and last gears decide the speed.

GEARS IN CHAIN

LAST GEAR TEETH

clockwise24 teeth · 60 rpm

anticlockwise12 teeth · 120 rpm

clockwise12 teeth · 120 rpm

Last gear: clockwise, 120 rpm.The driver (24 teeth) turns at 60 rpm. The middle gears change direction but not the overall ratio: 24 ÷ 12 × 60 = 120 rpm. An odd number of gears keeps the first and last turning the same way.

Take the test

10 questions · 10 minutes · assume ideal machines, no friction

Levers3 questionsGears & belts3 questionsPulleys & ramps2 questionsFluids & springs2 questions

Question 1 of 10Gears

00:00

Four gears are meshed in a straight line. Gear 1 turns clockwise.Which way does gear 4 turn?

0/10Learn the six rules above, then try again.Weakest: gears (0/2) · 29854925:48

Gears0/2Levers0/3Pulleys0/1Ramps0/1Hydraulics0/1Springs0/1Belts0/1

Question 1 · GearsAnswer: Anticlockwise · you chose nothingMeshed gears reverse direction. 1 clockwise, 2 anti, 3 clockwise, 4 anticlockwise. Size never changes direction.

Question 2 · GearsAnswer: 5 · you chose nothingTeeth passing are equal: 20 × 10 = 200 teeth, and 200 ÷ 40 = 5 turns of B.

Question 3 · LeversAnswer: 2 m · you chose nothingMoments balance when weight × distance match: 40 × 1 = 20 × d, so d = 2 m.

Question 4 · PulleysAnswer: 50 N · you chose nothingTwo strands share the load, so each carries 50 N. You pull 50 N but must pull twice as much rope.

Question 5 · RampsAnswer: C, 6 m · you chose nothingThe work (force × distance) is the same, so the longest ramp needs the smallest force, over a longer push.

Question 6 · HydraulicsAnswer: 200 N · you chose nothingPressure is equal throughout: 20 N per cm² × 10 cm² = 200 N. The large piston moves a tenth as far.

Question 7 · SpringsAnswer: B, side by side · you chose nothingSide by side, each spring carries half the weight, so the stretch halves. End to end, each carries all of it, so the stretch doubles.

Question 8 · BeltsAnswer: Anticlockwise · you chose nothingAn open belt keeps the same direction; crossing it reverses it, like meshed gears.

Question 9 · LeversAnswer: 30 cm · you chose nothingTurning effect (torque) is force × distance. The longest handle gives the same torque with a third of the force of the shortest.

Question 10 · LeversAnswer: Between the wheel and the handles · you chose nothingIt's a second-class lever: the load is between pivot and effort, so a small lift at the handles raises a heavy load.

HEGARTY & SIMS, 1994

Animate one part at a time

When people reason about pulley systems, their eyes move along the chain of cause and effect, part by part. Errors pile up further down the chain, so good solvers slow down there.

1Follow the chain from the inputStart where the force is applied and move one part at a time to the output.

2Count, don't pictureFor gears, count meshes to get direction. For pulleys, count supporting strands.

3Check the trade-offIf an answer saves force, it must cost distance. An option that saves both is wrong.

4Ignore size when it's about directionGear and pulley sizes change speed and force, never which way they turn.

Keep going

Spatial reasoningRotation and folding: the visual side of mechanics.Open

Diagrammatic reasoningFollow inputs through a chain of operations.Open

Numerical reasoningThe arithmetic behind ratios and forces.Open

References

Hegarty, M. (2004). Mechanical reasoning by mental simulation. Trends in Cognitive Sciences, 8(6), 280–285.
Hegarty, M., & Sims, V. K. (1994). Individual differences in mental animation during mechanical reasoning. Memory & Cognition, 22(4), 411–430.
Bennett, G. K. Bennett Mechanical Comprehension Test (manual, various editions). The Psychological Corporation.