- Momentum (HT)
- p = mv, momentum (kg m/s) = mass (kg) × velocity (m/s)
- Kinetic energy
- Eₖ = ½mv², kinetic energy (J) = ½ × mass (kg) × speed² (speed in m/s)
- Gravitational potential energy
- Eₚ = mgh, gravitational potential energy (J) = mass (kg) × gravitational field strength (N/kg) × height (m)
- Power, from energy and time
- P = E / t, power (W) = energy transferred (J) ÷ time (s)
- Power, from work done and time
- P = W / t, power (W) = work done (J) ÷ time (s)
- Efficiency, from energy
- Efficiency = useful output energy (J) ÷ total input energy (J). Efficiency has no unit; multiply by 100 for a percentage.
- Efficiency, from power
- Efficiency = useful power output (W) ÷ total power input (W). Efficiency has no unit; multiply by 100 for a percentage.
- Wave speed
- v = fλ, wave speed (m/s) = frequency (Hz) × wavelength (m)
- Charge flow
- Q = It, charge flow (C) = current (A) × time (s)
- Potential difference
- V = IR, potential difference (V) = current (A) × resistance (Ω)
- Power, from potential difference and current
- P = VI, power (W) = potential difference (V) × current (A)
- Power, from current and resistance
- P = I²R, power (W) = current² (current in A) × resistance (Ω)
- Energy transferred, from power and time
- E = Pt, energy transferred (J) = power (W) × time (s)
- Energy transferred, from charge and potential difference
- E = QV, energy transferred (J) = charge flow (C) × potential difference (V)
- Density
- ρ = m / V, density (kg/m³) = mass (kg) ÷ volume (m³)
- Motion with a steady acceleration
- v² − u² = 2as, final velocity² (final velocity in m/s) − initial velocity² (initial velocity in m/s) = 2 × acceleration (m/s²) × distance (m)
- Force and momentum (physics only, HT)
- F = mΔv / Δt, force (N) = mass (kg) × change in velocity (m/s) ÷ time taken (s)
- Elastic potential energy
- Eₑ = ½ke², elastic potential energy (J) = ½ × spring constant (N/m) × extension² (extension in m). This holds while the limit of proportionality is not passed.
- Specific heat capacity
- ΔE = mcΔθ, change in thermal energy (J) = mass (kg) × specific heat capacity (J/kg °C) × temperature change (°C)
- Specific latent heat
- E = mL, thermal energy for a change of state (J) = mass (kg) × specific latent heat (J/kg)
- Period
- T = 1 / f, period (s) = 1 ÷ frequency (Hz)
- Magnification of a lens (physics only)
- Magnification = image height ÷ object height. No unit: measure both heights in the same unit, such as mm.
- Force on a conductor (HT)
- F = BIl, force (N) = magnetic flux density (T) × current (A) × length of conductor in the field (m). The conductor is at right angles to the field.
- Transformers (physics only, HT)
- VₚIₚ = VₛIₛ, primary potential difference (V) × primary current (A) = secondary potential difference (V) × secondary current (A)
- Turns ratio (physics only, HT)
- Vₚ / Vₛ = nₚ / nₛ, primary potential difference (V) ÷ secondary potential difference (V) = primary turns ÷ secondary turns
- Pressure in a liquid (physics only, HT)
- p = hρg, pressure (Pa) = height of the column (m) × density (kg/m³) × gravitational field strength (N/kg)
- Gas at constant temperature (physics only)
- pV = constant, pressure (Pa) × volume (m³) = constant. For a fixed mass of gas.