Students often describe physics as “the math-and-memorization class.” They picture endless lists of words — kinematics, centripetal, isochronous, amplitude — layered on top of equations, and they brace for a year of flashcards and formulas. That picture is wrong, and it is wrong in a way that matters. Physics vocabulary is not a random pile of words. It is a construction kit: nearly every technical term is built from a small set of Greek and Latin roots, prefixes, and suffixes, snapped together like parts.
Once you know the parts, you stop memorizing and start reading. A student who knows that centri- means center and -petal means seeking does not need to memorize that a centripetal force points inward — the word announces itself. Multiply that across a hundred terms and the savings are enormous. This is one of the highest-leverage study habits in the whole course, and it is the one most students never discover.
Why roots beat words
Consider the alternative. If you memorize centrifugal as an undifferentiated string of sounds, it sits in memory as a single brittle fact. Swap one syllable and the whole thing collapses — which is exactly why so many students confuse centripetal and centrifugal on a test. But if you know that centri- means center, -petal means seeking, and -fugal means fleeing, each word becomes self-explanatory and nearly impossible to forget — and the same roots now help with centripetal, centrifugal, concentric, and center of mass for free.
This is the difference between learning that scales and learning that doesn’t. Memorizing words is linear: a hundred terms cost a hundred units of effort. Learning roots is exponential: thirty roots unlock several hundred words. We ask students in this course to keep a running roots-and-symbols page at the back of the lab notebook and to add to it every time a new prefix, suffix, or unit symbol appears. By the second unit, the page does most of the work that flashcards used to do.
Don’t memorize the word. Take it apart, name the pieces, and the meaning falls out.
The core roots
Below is the working set — the parts that appear again and again across motion, force, energy, and waves. Learn these first. They earn their keep within the first month.
| Part | Meaning | Example | What it tells you |
|---|---|---|---|
| kine- / -matics | motion | kinematics | The study of motion itself — describing it without yet asking what causes it. |
| dyna- | force, power | dynamics | Motion together with the forces that cause it — where Newton’s laws live. |
| veloc- | swift | velocity | Speed with a direction attached — a vector, not just a number. |
| accel- | to hasten | acceleration | How fast the velocity itself is changing — the slope of a velocity graph. |
| grav- | heavy | gravity, gravitation | The mutual pull every mass has on every other — and what gives an object weight. |
| centri- / centro- | center | centripetal, concentric | Toward the center — a centripetal force points inward, holding an object in its circle. |
| -petal / -fugal | seeking / fleeing | centripetal, centrifugal | Which way it points — petal seeks the center, fugal flees it. |
| peri- | around, near | perimeter, perigee | Near or around — perigee is an orbit’s nearest point to Earth. |
| apo- / ap- | away, far | apogee | Far off — apogee is an orbit’s farthest point. |
| iso- | equal, same | isochronous | Equal in some respect — a pendulum’s swings are isochronous: each takes the same time. |
| chrono- / -chron- | time | chronometer, isochronous | Anything to do with time — a chronometer keeps time precisely. |
| thermo- / -thermic | heat | thermometer, thermodynamics | Heat, temperature, and the energy that flows as heat. |
| baro- | weight, pressure | barometer | Pressure — a barometer measures the pressure of the air. |
| -stat / statics | standing, at rest | statics, hydrostatic | Bodies at rest or forces in balance — nothing accelerating. |
| flu- / fluid- | to flow | fluid, flux | Anything that flows — a fluid is a liquid or a gas. |
| dens- | thick, packed | density | How much mass is packed into a given volume. |
| torqu- | to twist | torque | The twisting effect of a force about a pivot — what turns a wrench. |
| ampl- | wide, large | amplitude | Size of a swing — amplitude is the greatest displacement from rest. |
| -tude | magnitude, size | magnitude, amplitude | The size of a quantity, setting its direction aside. |
| kilo-, milli-, micro- | 1000, 1/1000, one-millionth | kilometer, millisecond | SI prefixes that scale a base unit up or down by powers of ten. |
| -metry / -meter | measure | meter stick, odometer | A tool or act of measuring — an odometer measures distance traveled. |
High-value clusters by unit
It helps to learn parts in the company they keep. The same handful of roots recur within each unit, so a student who masters one cluster has effectively pre-read the vocabulary for the weeks ahead.
Motion & the laws of force. The opening units lean on kine-, dyna-, veloc-, and accel-. Knowing these turns kinematics, dynamics, velocity, and acceleration into a connected web — and it forces two distinctions students trip on: distance vs displacement (how far you traveled versus how far you ended up from the start) and speed vs velocity (a bare number versus a number with a direction).
Circular motion & gravitation. This unit runs on centri-, -petal/-fugal, peri-/apo-, and grav-. A student who internalizes these reads centripetal, centrifugal, perigee, apogee, and gravitation on sight — the whole vocabulary of anything that orbits or turns, decoded from a handful of parts.
Energy, momentum & simple harmonic motion. The middle units are built from -tude, ampl-, iso-, chrono-, and thermo-. Amplitude, magnitude, isochronous, period, and frequency all decode from this set — the language of anything that swings, stores energy, or repeats. Here the key distinction is scalar vs vector: a scalar has size only, a vector has size and direction.
Torque, rotation & fluids. The back half of the course returns to torqu-, baro-, flu-, dens-, and statics. Torque, density, pressure, and buoyancy all tie back to force and flow — along with the last distinction that trips students: mass vs weight (how much matter there is, versus the force gravity exerts on it). Keep the SI base units and their symbols on the same page — the meter (m), the kilogram (kg), the second (s) — and the ones built from them: the newton (N) for force, the joule (J) for energy, the watt (W) for power, the pascal (Pa) for pressure, and the hertz (Hz) for frequency.
How to actually use this
Don’t try to swallow the table in one sitting. Keep this page open during reading and lab, and each time you hit an unfamiliar term, break it apart out loud before you look it up. Name the parts, guess the meaning, then check. The guessing is the point: that small act of retrieval is what fixes the root in memory. Within a few weeks the habit becomes automatic, and the “memorization class” quietly turns into a class you can read your way through — leaving your effort free for the part of physics that actually rewards it: the problem-solving.