# Physics

**Type:** Topic
**Words:** 83

## About

Matter, motion, forces, energy, electricity, waves, and the physical laws of nature.

## Words by Level

### A1
- light — Not weighing much; easy to lift or carry.; frequency rank 526

### A2
- matter — A situation, subject, or affair that is being dealt with or considered.; frequency rank 309
- power — The ability to control or influence people and events.; frequency rank 499
- force — Physical power or strength used on something.; frequency rank 849
- energy — The strength and ability to be active without getting tired.; frequency rank 1232
- pressure — A feeling of stress caused by demands or difficulties.; frequency rank 1270
- speed — How fast something moves or happens.; frequency rank 1432
- heat — The quality of being hot; high temperature.; frequency rank 1621
- weight — How heavy something or someone is.; frequency rank 1705
- physical — Relating to the body rather than the mind.; frequency rank 2131
- wave — To move your hand from side to side to greet someone or say goodbye.; frequency rank 2505
- temperature — A measure of how hot or cold something is.; frequency rank 3165
- electric — Using, producing, or powered by electricity.; frequency rank 3235

### B1
- mass — A large amount or quantity of something with no clear shape.; frequency rank 2452
- current — Happening or existing now; belonging to the present time.; frequency rank 2600
- nuclear — Using the energy released when atoms are split or joined.; frequency rank 2902
- electricity — The energy carried by the flow of electric charge, used to power lights, machines, and devices.; frequency rank 3094
- radiation — Energy that travels as rays, waves, or particles, such as heat or light.; frequency rank 4417
- tension — A feeling of worry, nervousness, or unease, often in difficult situations.; frequency rank 4884
- physics — The science that studies matter, energy, and how they affect each other.; frequency rank 5210
- volume — How loud a sound is.; frequency rank 5724
- frequency — How often something happens within a period of time.; frequency rank 6500
- mechanical — Operated by or relating to machines or tools.; frequency rank 6729
- reflection — An image seen in a mirror or shiny surface.; frequency rank 6977
- voltage — the electric potential difference between two points, equal to energy transferred per unit electric charge and measured in volts; frequency rank 15666
- electron — A tiny particle inside an atom that carries a negative electric charge.; frequency rank 17165

### B2
- motion — The act or process of moving; movement.; frequency rank 3093
- resistance — The act of fighting against or refusing to accept something.; frequency rank 3763
- laser — A device that produces a narrow, powerful beam of light.; frequency rank 5221
- circuit — A complete path that an electric current flows around.; frequency rank 5924
- fluid — A liquid; a substance that flows.; frequency rank 5995
- conductor — The person who leads an orchestra or other musical group.; frequency rank 9166
- particle — A very small piece of something.; frequency rank 9745
- friction — The rubbing of one object or surface against another.; frequency rank 14463
- vibration — A continuous shaking movement, or the act of shaking quickly back and forth.; frequency rank 17059
- relativity — (physics) The scientific theory that space and time are not fixed but depend on the observer's motion.; frequency rank 18393
- compression — the act of pressing or squeezing something into a smaller space; frequency rank 19273
- wavelength — a shared orientation leading to mutual understanding; frequency rank 21027
- transistor — A small electronic part used in devices to control or boost electrical signals.; frequency rank 31357

### C1
- gravity — The natural force that pulls objects toward the earth or toward each other.; frequency rank 4160
- vacuum — A space that contains no matter or air.; frequency rank 6310
- magnetic — Having the properties of a magnet, or able to attract metal such as iron.; frequency rank 6570
- interference — The act of getting involved in something that does not concern you.; frequency rank 7730
- fusion — The act of joining separate things into one, or the result of doing so.; frequency rank 10433
- momentum — The driving force that keeps an idea, process, or campaign moving forward.; frequency rank 11302
- thermal — relating to heat, temperature, or the transfer of heat; frequency rank 11535
- spectrum — A wide range of related ideas, opinions, qualities, or things.; frequency rank 11765
- rotation — The act of turning around a central point or axis.; frequency rank 11894
- density — How much of something there is in a given space or area.; frequency rank 14680
- magnetism — The physical force by which magnets attract or repel iron and other materials.; frequency rank 21267
- torque — a twisting force; frequency rank 22607
- radioactivity — Spontaneous emission of ionizing radiation as a consequence of a nuclear reaction, or directly from the breakdown of an unstable nucleus.; frequency rank 22820
- optics — the branch of physics concerned with light, vision, and the behavior of electromagnetic radiation; frequency rank 24373
- inertia — a disposition to remain inactive or inert; frequency rank 31234
- capacitor — an electrical component that stores energy in an electric field between separated conductors
- convection — the transfer of heat through the movement of a liquid or gas

### C2
- radioactive — exhibiting or caused by radioactivity; frequency rank 9661
- gravitational — Relating to or caused by gravity.; frequency rank 12389
- equilibrium — A state of balance in which opposing forces or influences cancel each other out.; frequency rank 23040
- photon — The quantum of light and other electromagnetic energy, regarded as a discrete particle having zero rest mass, no electric charge, and an indefinitely long lifetime. It is a gauge boson.; frequency rank 23769
- kinetic — Relating to or produced by movement.; frequency rank 26179
- angular — Having sharp corners or pointed shapes rather than smooth, rounded ones.; frequency rank 33800
- buoyancy — irrepressible liveliness and good spirit; frequency rank 41411
- elasticity — The ability of a material to return to its original shape after being stretched or squeezed.; frequency rank 42510
- thermodynamics — The science of the conversions between heat and other forms of energy.; frequency rank 44278
- electromagnetism — magnetism produced by an electric current; frequency rank 47053
- diffraction — when light passes sharp edges or goes through narrow slits the rays are deflected and produce fringes of light and dark bands; frequency rank 92428

### C2+
- amplitude — the extent or magnitude of something; the range of a wave
- vector — a quantity with magnitude and direction; a carrier of disease
- velocity — speed in a given direction; rapidity of motion
- acceleration — the rate of increase of speed or, more generally, the act of speeding up
- dispersion — the act of scattering or the state of being spread over a wide area
- entropy — a measure of disorder or of energy unavailable for work in a system
- conduction — the transmission of heat, electricity, or signals through a medium
- displacement — the act of moving something from its place or the resulting shift
- fission — the splitting of an atomic nucleus or a cell into parts
- magnet — an object that attracts iron; a person or thing that draws others
- oscillation — a regular movement back and forth between two points or states
- physicist — a scientist who specializes in the study of physics
- quantum — a discrete quantity of energy, or the smallest possible amount
- refraction — the bending of light or other waves as they pass between media
- resonance — the quality of being deep, full, and reverberating; sympathetic vibration
- viscosity — a fluid's resistance to flow; thickness or stickiness