Your FREE POSS Flashcards 2026 – 200+ Cards

2 — the load hangs on 2 rope segments, so each carries half the load.

How much a machine multiplies your effort: load ÷ effort. An MA of 4 means a 1 lb effort balances a 4 lb load.

1 — it only changes the direction of the force, saving no effort.

Count the rope segments that actually support the load — that number is the MA.

150 lb — the load is shared by 2 supporting rope segments (300 ÷ 2).

75 lb — 300 ÷ 4 supporting rope segments.

Work. What you save in force you pay back in distance — more rope to pull, a longer push, etc.

effort × effort-arm = load × load-arm. A longer effort arm multiplies your force.

The fixed pivot point a lever turns on. Its position defines the lever's class.

Fulcrum in the middle. Seesaw, crowbar, pliers — can multiply force or just change direction.

Load in the middle. Wheelbarrow, bottle opener — always multiplies force (MA > 1).

Effort in the middle. Tweezers, your forearm — trades force for speed and range (MA < 1).

Driven-gear teeth ÷ driver-gear teeth. 30 teeth ÷ 10 teeth = 3:1.

Opposite directions. An idler gear between them reverses direction but doesn't change the ratio.

More teeth = slower rotation but more torque. A 3:1 gear turns one-third the speed with three times the torque.

Decreases output speed and increases torque — turning a fast, low-torque motor into slow, high-torque output.

A turning or twisting force. Slowing rotation increases available torque.

A pressure change in a confined fluid is transmitted equally throughout it — the basis of hydraulics.

Pressure = force ÷ area (P = F ÷ A). Rearranged: force = pressure × area.

Pressure is equal throughout the fluid, so a larger output piston (more area) makes a larger force: F = P × A.

P = F ÷ A = 50 ÷ 2 = 25 psi throughout the fluid.

F = P × A = 25 × 20 = 500 lb.

Using compressed air or gas to transmit force or do work — like hydraulics but with a compressible fluid.

Moisture from the compressed air before it enters the system.

Work = force × distance.

The resistance force when two surfaces move against each other. It causes wear and heat and wastes energy.

They replace sliding contact with rolling contact (balls/rollers) or a lubricant film, so far less surface drags.

Rolling friction is much smaller, which is why ball and roller bearings cut energy loss sharply.

Stores rotational (kinetic) energy and releases it smoothly, evening out an engine's power delivery.

To convert steam back to water (condense it) so it can be reused.

Increased belt slippage — the belt can't grip and transmit power reliably.

A hydraulic motor — it turns fluid pressure and flow into rotating mechanical output.

Transfers rotational power from the engine to the transmission, allowing smooth power transfer in an automatic.

To move fluid by adding energy to it — raising its pressure or moving it through piping.

Output force increases — force is proportional to area (F = P × A).

It lowers pressure — pressure = force ÷ area, so more area means less pressure.

It multiplies your force — you trade a longer push for a larger output force.

Speed increases, torque decreases — the smaller gear spins faster with less torque.

Pressure = force ÷ area; a tiny tip area concentrates the same force into very high pressure.

Hook the cable at the center of gravity so the beam stays level — weight is balanced on each side of the lift point.

A basic device that changes the size or direction of a force: lever, pulley, wheel-and-axle, inclined plane, wedge, and screw.

A ramp — it lets you raise a load with less force over a longer distance (trading force for distance).

Two inclined planes back to back; it splits or lifts by converting a push into sideways force (axe, chisel).

An inclined plane wrapped around a cylinder; it converts rotation into linear force (jacks, bolts).

A large wheel fixed to a smaller axle; turning the wheel multiplies force at the axle (or vice versa).

An object stays at rest or in motion unless acted on by a net force.

Force = mass × acceleration (F = ma). More force or less mass means more acceleration.

For every action there is an equal and opposite reaction.

The point where an object's weight is balanced. Supporting it there keeps the object level and stable.

A low center of gravity and a wide base — it's harder to tip.

Stored energy due to position or condition — a raised weight or a compressed spring.

Energy of motion. A moving or rotating object (like a flywheel) carries kinetic energy.

By compressing or stretching; it stores potential energy and pushes back toward its rest length (Hooke's law).

To control the flow of a fluid — open, close, or throttle flow in a pipe or system.

A valve that allows flow in only one direction, preventing backflow.

Converts energy (electrical or hydraulic) into rotating mechanical motion.

Converts mechanical motion into electrical energy — the reverse of a motor.

To support a rotating shaft while reducing friction so it turns freely.

Length of the ramp ÷ its height — a longer, gentler ramp needs less force.

More effort-arm (leverage) multiplies your torque for the same hand force.

Torque increases — torque = force × distance from the pivot.

It wastes input energy as heat, so output work is always less than input work.

It forms a film between surfaces, reducing friction, wear, and heat, and carries heat away.

Changing the direction of a force — a fixed pulley lets you pull down to lift a load up.

Ratio 3:1; the driven gear turns one-third the speed with three times the torque.

Its stored rotational energy briefly supplies extra torque to carry the machine through the spike.

An (effectively) incompressible confined liquid, which passes the pressure equally everywhere (Pascal's principle).

Air is compressible (springy, lighter duty); liquid is nearly incompressible, giving stiffer, higher-force control.

It cools and condenses spent steam back to water so the feed pump can reuse it.

Enough tension lets the belt grip the pulleys and transmit power without slipping.

Too little tension, an overloaded or over-speeded drive, or worn/greasy surfaces reduce grip.

Work = force × distance. Doing the same work with less force requires more distance.

Produces a larger force, since force = pressure × area.

No. All math is done by hand, so practice mental math, unit conversions, and clean arithmetic.

Change ÷ original × 100. From 150 to 180: change 30, 30 ÷ 150 = 0.20 = 20%.

Always the ORIGINAL (starting) value. Dividing by the new value is the most common mistake.

part = percent × whole. Turn the percent into a decimal first: 25% of 80 = 0.25 × 80 = 20.

Set the two ratios equal as fractions and cross-multiply: a/b = c/d means a × d = b × c.

Ratio is 1:3, so 45 ÷ 3 = 15 operators.

distance = rate × time. Rearranged: rate = distance ÷ time, time = distance ÷ rate.

Total distance ÷ total time. 120 km in 1.5 h = 120 ÷ 1.5 = 80 km/h.

Divide by 60. 90 minutes = 90 ÷ 60 = 1.5 hours.

Divide then multiply by 100: 3 ÷ 4 = 0.75 = 75%.

Divide by 100: 25 ÷ 100 = 0.25.

Divide by 1,000. 300 L/min × 120 min = 36,000 L = 36 m³.

0.5 and 50%.

0.25 and 25%.

0.2 and 20%.

0.125 and 12.5%.

0.333… ≈ 33%.

A quarter of 600 = 150 L. Time = 150 ÷ 20 = 7.5 minutes.

Parentheses, then exponents, then multiply/divide (left to right), then add/subtract (left to right).

Match each value to its spot, convert units so they agree, then compute in order. The POSS gives you the formula.

A ballpark answer makes an obviously wrong choice (often from a unit slip) easy to spot before you commit.

Subtract 12: 6x = 36. Divide by 6: x = 6.

Convert so the units agree (minutes↔hours, inches↔feet, liters↔m³). Many POSS math items hinge on one conversion.

5/3 = A/40, so A = 5 × 40 ÷ 3 ≈ 66.67 kg.

Total ÷ number of parts. 320 tons over 8 cars = 40 tons each.

320 × 7 = 2,240 tons; 2,240 ÷ 40 = 56 cars.

Net = 100 − 75 = 25 L/min added.

π ≈ 3.14159. Circumference = π × diameter.

length × width.

½ × base × height.

Divide the part by the whole and multiply by 100. 30 is what % of 150? 30 ÷ 150 × 100 = 20%.

Change 30 MW ÷ original 150 = 0.20 = 20% increase.

Multiply by 60. 1.5 hours = 90 minutes.

Multiply by 12. 3 feet = 36 inches.

Multiply by 1,000. 36 m³ = 36,000 L.

0.4 and 40%.

0.6 and 60%.

Move the decimal one place left. 10% of 250 = 25.

Half of 10%. 10% of 250 = 25, so 5% = 12.5.

Double 10%. 10% of 250 = 25, so 20% = 50.

Change 50 ÷ original 200 = 0.25 = 25% decrease.

Sum of values ÷ count of values.

time = distance ÷ rate.

rate = distance ÷ time.

Inflow rate − outflow rate. Positive = filling, negative = draining.

6,000 ÷ 25 = 240 minutes.

300 × 120 min = 36,000 L.

9x = 3 × 45 = 135, so x = 15.

Divide both by 9: 1:5.

2 × (length + width).

Multiply by 100. 0.35 = 35%.

0.75 × 80 = 60.

A rate per single unit — e.g. liters per minute, miles per hour, dollars per item.

Re-read what was asked and confirm your number answers it, in the right units, before selecting.

Add 4: 2x = 14. Divide by 2: x = 7.

Division — 'liters per minute' means liters ÷ minutes; 'cost per item' means cost ÷ items.

5 parts total: each part 10 kg, so 20 kg and 30 kg.

1.5 h × 60 = 90 min; 90 × 60 = 5,400 seconds.

The single overall point the whole passage supports — not one detail. Pick the answer choice that covers the entire passage.

Main idea = what the passage is about (whole). Supporting detail = a fact, number, or example that proves it (one sentence).

Always in the passage itself. Never use outside plant knowledge — answer only from what the text states or implies.

Scan back to the exact sentence that states the fact rather than relying on memory; the answer is one line, not the whole passage.

Something the passage implies but does not state outright. Choose the conclusion the text supports — reject anything not backed by these words.

A choice that is true in the real world but NOT supported by the passage. Pick what the text backs, not what merely sounds reasonable.

Use the surrounding sentence. Substitute each answer choice into the sentence and keep the one that preserves the meaning.

It tells you whether you need the gist (main idea) or one buried fact (detail), so you skim or hunt accordingly — saving time on the clock.

36 questions in 30 minutes — five passages, each followed by several multiple-choice questions.

Technical material like power-plant operator training and safety manuals — but no outside knowledge is required to answer.

Track the ORDER of steps (first, then, before, until) and any 'if/then' conditions that change what to do.

Order and timing: first, then, next, before, after, until, unless. Underline them to keep the steps straight.

Choose the option that covers the whole passage. A title that fits only one paragraph is too narrow; one beyond the text is too broad.

Skim for the gist first, then read closely only the part a question points to. The 30-minute clock rewards targeted rereading.

It asks what logically follows from the passage. Choose the statement the passage's facts support — not an unsupported guess.

Don't memorize them. Note where each value is, then scan back to the exact figure a question asks about.

A fact can be verified from the text; an opinion is the author's judgment. Detail questions usually target facts.

Answer strictly from the text — the correct choice is stated in or directly supported by the passage, not by outside knowledge.

Drop choices that contradict the text, go beyond it, or are too extreme. The right answer is supported and on-scope.

It prevents answering the wrong question — confusing the main idea with a detail, or a cause with an effect.

The sentence (often first) that states a paragraph's main point; the rest of the paragraph supports it.

Combine the main idea with the most important supporting point — 'X happens because/so that Y.'

To suggest without stating directly. An implied idea is supported by the text but not written word-for-word.

A cause makes something happen; an effect is the result. Signal words: because, since, so, therefore, as a result.

Read the first and last sentences of each paragraph for structure, then dive into detail only where a question points.

The attitude the writing conveys (neutral, cautionary, informative). Technical POSS passages are usually neutral and factual.

Match each choice against the text; the correct one is stated or directly supported, the rest contradict or overreach.

So you can jump straight back to them when a detail question asks for a specific figure or term.

To illustrate or prove the main idea with a concrete case; it backs the point but is not the point itself.

It adds information the passage never mentions, or pushes a claim further than the text does.

Nearby words that hint at an unfamiliar word's meaning — a definition, example, or contrast in the same sentence.

Note the order and any warnings/conditions; a step done out of order or ignoring a condition is the wrong answer.

Re-read the exact line in the passage; the better answer is the one the text more directly supports.

They set scope. A choice saying 'all' is wrong if the passage only supports 'some' — watch absolute words.

20 questions in 10 minutes — Picture Series, Picture Comparison, and Picture Progression items.

Isolating the ONE rule that changes from figure to figure, then applying it again to predict the next figure.

Figures that change by a consistent rule from one to the next; you pick the figure that comes next.

Turns it around a center point. A 90° clockwise turn moves up→right→down→left.

Flips it across a line into a mirror image, reversing left and right.

A rotation keeps handedness; a reflection reverses left and right. The classic trap is a mirror image when only a turn was applied.

Back at its starting orientation — four 90° turns make a full 360° circle.

Right. Up→right(1)→down(2)→left(3)→up(4)→right(5).

Rotation, reflection, adding/removing an element, and changing count or size.

Track each change (e.g. rotation AND an added dot) separately, then apply both to the next figure.

7 ÷ 3 leaves remainder 1, so the 7th matches the 1st shape in the cycle.

Pick a reference point (an arrow's tip or a marked corner) and step it through the rotation one move at a time.

The number of items (dots, lines, sides) increases or decreases by a steady amount each step.

The figure grows or shrinks by a consistent step — track the direction of the change.

Identify the rule the others share, then pick the one figure that breaks it.

A figural item asking how two figures relate — what changed (rotation, reflection, added element) between them.

A figural item where figures change step by step by a rule; you continue the rule to the next figure.

It points down — a half turn reverses the direction.

Both reward finding a consistent rule and applying it one more step — repeating cycles, steady counts, or steady changes.

It tests reasoning, not memorized facts — so training your eye to spot the single rule builds the biggest gains.

A reflected letter is reversed (mirror image); a rotated letter keeps its handedness, just turned.

Compare just the first two figures and name the single change before looking at later figures or the choices.

It points left — a quarter turn the other way.

The same as a 90° counterclockwise turn.

Find the steady step (e.g. each shape one size smaller) and apply it once more.

5 circles — one new circle per frame.

Continue the alternation; an even or odd position tells you the color of the next figure.

Black — odd positions (1,3,5,7) are black.

The count of squares grows; track how many and any color or shading pattern.

A pentagon has 5 vertices; 360° ÷ 5 = 72°, so it looks the same again after 5 steps.

A horizontal flip then a vertical flip equals a 180° rotation.

Two changes: direction (clockwise step) and tail length (longer each step). Apply both.

Overlay them mentally and note the single difference — rotation, reflection, or an added/removed element.

When the rule is a rotation, eliminate any mirror-image (flipped) choice first.

Top-right (one clockwise step) and one size larger.

Look for added/removed elements or a count/size change instead.

A steady increase or decrease in sides/vertices is a common progression rule.

Four — 4 × 90° = 360°.

A steady, rule-based change from one figure to the next that you extend to find the answer.

Track the shading/color pattern of the inner shape and any size or rotation change.