AFCT flashcards
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32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Connotation
- The emotional or evaluative association a word carries beyond its literal meaning, such as the negative tone of 'stingy' versus the neutral 'economical'.
- Prefix sub-
- A prefix meaning under, below, or beneath, as in submarine (under the sea) or substandard (below an accepted standard).
- Antonym
- A word with a meaning opposite to another word, such as hot and cold or expand and contract.
- Root -dict-
- A Latin root meaning to say or speak, appearing in predict (say beforehand), dictate (speak for recording), and verdict (true saying).
- Main idea
- The central point that a whole paragraph supports, broader than any single supporting detail and often stated in the first or last sentence.
- Valid inference
- A conclusion logically forced by evidence in the passage rather than merely plausible, requiring no assumptions from outside the text.
- Author's purpose
- The reason a passage was written, generally to inform or explain, to persuade or argue, or to entertain or narrate.
- Contrast signal
- A transition word such as however, whereas, or on the other hand that signals the author is reversing or qualifying the previous idea.
- Percent change formula
- Percent change equals the difference between new and old values divided by the old value, then multiplied by 100.
- Average (mean)
- The sum of all values divided by the number of values; to find a missing value, multiply the mean by the count and subtract known values.
- Simple interest
- Interest computed as principal times annual rate as a decimal times time in years, written I = P x r x t.
- Combined work rate
- When two workers complete a job in times a and b alone, their combined time together is 1 divided by (1/a + 1/b).
- Quadratic formula
- For ax^2 + bx + c = 0, x equals negative b plus or minus the square root of b squared minus 4ac, all divided by 2a.
- Pythagorean theorem
- In a right triangle, the square of the hypotenuse equals the sum of the squares of the other two sides: a^2 + b^2 = c^2.
- Slope of a line
- The change in y divided by the change in x between two points; parallel lines share a slope and perpendicular slopes multiply to negative one.
- Negative exponent rule
- Any nonzero base raised to a negative exponent equals one divided by that base raised to the positive version of the exponent.
- Photosynthesis equation
- Six carbon dioxide molecules plus six water molecules plus light energy produce one glucose molecule and six oxygen molecules inside chloroplasts.
- pH scale
- A 0 to 14 scale of acidity: below 7 is acidic, 7 is neutral, above 7 is basic, and each whole step means a tenfold change.
- Newton's second law
- The acceleration of an object equals the net force acting on it divided by its mass, commonly written as force equals mass times acceleration.
- Earth's outer core
- The liquid layer of molten metal beneath Earth's mantle and surrounding the solid inner core; its motion generates the planet's magnetic field.
- Ohm's law
- Voltage across a conductor equals current multiplied by resistance, written V = I x R with volts, amperes, and ohms as units.
- Parallel circuit resistance
- Total resistance is found by adding the reciprocals of each branch resistance and taking the reciprocal of that sum; voltage is equal across branches.
- Electrical power
- Power in watts equals voltage times current, and can also be computed as current squared times resistance or voltage squared divided by resistance.
- Diode
- A semiconductor component that permits current to flow in only one direction, acting as a one-way valve in a circuit.
- Four-stroke cycle
- The sequence of intake, compression, power, and exhaust strokes that a piston repeats in a standard gasoline engine.
- Alternator function
- A belt-driven generator that produces electricity while the engine runs, recharging the battery and powering the vehicle's electrical systems.
- Ripsaw versus crosscut saw
- A ripsaw has chisel-like teeth for cutting along the wood grain, while a crosscut saw has knife-like teeth for cutting across it.
- Lever mechanical advantage
- The ratio of effort arm length to resistance arm length; lengthening the effort arm reduces the force needed to move a load.
- Movable pulley advantage
- A movable pulley shares the load among supporting rope segments, giving mechanical advantage equal to the number of segments lifting the load.
- Pressure formula
- Pressure equals force divided by area, so spreading the same force over a larger area produces lower pressure.
- Gear ratio
- The number of teeth on the driven gear divided by teeth on the driving gear; larger driven gears increase torque while reducing speed.
- Inclined plane advantage
- Mechanical advantage equals the length of the incline divided by its height, so a longer gentle ramp needs less force over more distance.