| base SI | kg, m, s, A, K, mol |
| T G M k | 10¹² 10⁹ 10⁶ 10³ |
| c m µ n | 10⁻² 10⁻³ 10⁻⁶ 10⁻⁹ |
| scalar | size only (speed, mass, energy) |
| vector | size + direction (velocity, force) |
| K | °C + 273 |
| speed | distance ÷ time |
| acceleration | a = (v − u) ÷ t |
| d–t gradient | speed |
| v–t gradient | acceleration |
| v–t area | distance |
| free fall | g ≈ 10 m/s² |
| weight | W = mg (g = 10 N/kg) |
| density | ρ = m ÷ V |
| Newton 2 | F = ma (resultant) |
| balanced | constant velocity / rest |
| action–reaction | equal, opposite, different bodies |
| terminal velocity PURE | air resistance = weight |
| pressure | p = F ÷ A (Pa) |
| liquid PURE | p = hρg |
| hydraulics PURE | F₁/A₁ = F₂/A₂ |
| atm PURE | ≈ 1.0 × 10⁵ Pa = 760 mm Hg |
| moment | F × ⟂ distance (N m) |
| equilibrium | Σ clockwise = Σ anticlockwise, ΣF = 0 |
| stability PURE | low CG, wide base |
| kinetic | Ek = ½mv² |
| gravitational | Ep = mgh |
| work | W = F × s |
| power | P = E ÷ t = W ÷ t |
| efficiency PURE | useful out ÷ total in × 100% |
| stores | kinetic, GPE, elastic, chemical, nuclear, internal |
| transfers | mechanical, electrical, heating, waves |
| conservation | total energy constant |
| falling | mgh = ½mv² |
| solid | close, regular, vibrate |
| liquid | close, irregular, slide |
| gas | far, random, fast |
| temperature | average KE of particles |
| internal energy | total KE + PE |
| change of state | temp constant |
| gas pressure | particles hit walls |
| conduction | vibrations + free electrons (solids) |
| convection | density change → currents (fluids) |
| radiation | infrared, no medium |
| best emitter/absorber | dull black |
| worst | shiny silver/white |
| more radiation | hotter, larger area |
| heating | E = mcΔθ |
| change of state | E = mL |
| heat capacity | C = mc |
| water | c = 4200 J/(kg K) |
| evaporation | any temp, surface, cools |
| boiling | fixed temp, throughout |
| faster evaporation | hotter, wind, larger area, low humidity |
| wave equation | v = fλ |
| period | T = 1 ÷ f |
| transverse | ⟂ — light, water, EM |
| longitudinal | ∥ — sound (C & R) |
| loudness / pitch | amplitude / frequency |
| echo | d = vt ÷ 2 |
| ultrasound PURE | > 20 kHz |
| order (f ↑) | radio, micro, IR, visible, UV, X, γ |
| speed | 3.0 × 10⁸ m/s |
| ionising | UV (high), X, γ |
| all EM | transverse, no medium |
| reflection | i = r |
| refractive index | n = sin i ÷ sin r = c ÷ v |
| critical angle PURE | sin c = 1 ÷ n |
| TIR PURE | dense → less dense, i > c |
| plane mirror | virtual, upright, same size, lat. inverted |
| beyond 2F | real, inverted, diminished |
| at 2F | real, inverted, same size |
| F to 2F | real, inverted, magnified |
| inside F | virtual, upright, magnified |
| rays | parallel → F · centre → straight |
| charge | Q = It |
| p.d. / e.m.f. | V = W ÷ Q |
| resistance | R = V ÷ I |
| wire | R ∝ L ÷ A |
| power | P = VI = I²R = V²/R |
| energy | E = VIt = Pt |
| cost | kWh × rate |
| series | I same; V adds; R = R₁ + R₂ |
| parallel | V same; I adds; 1/R = 1/R₁ + 1/R₂ |
| ammeter | series |
| voltmeter | parallel |
| conventional current | + → − |
| potential divider PURE | V₂ = R₂/(R₁+R₂) × V |
| NTC / LDR PURE | R ↓ hotter / brighter |
| live | brown — fuse + switch here |
| neutral | blue |
| earth | green/yellow — metal case |
| fuse | just above normal I |
| double insulation | no earth needed |
| hazards | damp, bad insulation, overheating |
| ohmic | straight line through origin |
| filament lamp | curve, R ↑ with temp |
| diode | one direction only |
| rubbing | only electrons move |
| field lines | out of +, into − |
| precipitator | charged smoke → plates |
| field lines | N → S |
| iron / steel | temporary / permanent |
| wire | circles — right-hand grip |
| solenoid | stronger: turns, I, iron core |
| force | Fleming's LEFT: Field, Current, Motion |
| induced e.m.f. PURE | faster, stronger, more turns |
| transformer PURE | Vs/Vp = Ns/Np · VpIp = VsIs |
| notation | ᴬZX · A = p + n |
| α | He nucleus, most ionising, paper |
| β⁻ | electron, mm Al |
| γ | EM wave, thick lead |
| half-life | time for half to decay |
| α decay PURE | A −4, Z −2 |
| β decay PURE | A same, Z +1 |