AQA GCSE Physics equations

AQA GCSE Physics

Every equation you need for AQA GCSE Physics, grouped by topic, with the symbols, quantities and units. Some are printed on the equation sheet in the exam and some you must recall from memory — always check the current AQA equation sheet for your exam year.

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Energy

In words	Symbols	Quantities & units
kinetic energy = ½ × mass × speed²	Eₖ = ½ m v²	Eₖ (J), m (kg), v (m/s)
gravitational PE = mass × gravitational field strength × height	Eₚ = m g h	Eₚ (J), m (kg), g (N/kg), h (m)
elastic PE = ½ × spring constant × extension²	Eₑ = ½ k e²	Eₑ (J), k (N/m), e (m)
change in thermal energy = mass × specific heat capacity × temperature change	ΔE = m c Δθ	ΔE (J), m (kg), c (J/kg°C), Δθ (°C)
power = energy transferred ÷ time	P = E ÷ t	P (W), E (J), t (s)
efficiency = useful output energy ÷ total input energy	efficiency = Eₒᵤₜ ÷ Eᵢₙ	ratio (0–1 or ×100 for %)

Electricity

In words	Symbols	Quantities & units
charge = current × time	Q = I t	Q (C), I (A), t (s)
potential difference = current × resistance	V = I R	V (V), I (A), R (Ω)
power = potential difference × current	P = V I	P (W), V (V), I (A)
power = current² × resistance	P = I² R	P (W), I (A), R (Ω)
energy transferred = power × time	E = P t	E (J), P (W), t (s)
energy transferred = charge × potential difference	E = Q V	E (J), Q (C), V (V)

Forces & motion

In words	Symbols	Quantities & units
weight = mass × gravitational field strength	W = m g	W (N), m (kg), g (N/kg)
work done = force × distance	W = F s	W (J), F (N), s (m)
force = spring constant × extension	F = k e	F (N), k (N/m), e (m)
momentum = mass × velocity	p = m v	p (kg m/s), m (kg), v (m/s)
resultant force = mass × acceleration	F = m a	F (N), m (kg), a (m/s²)
acceleration = change in velocity ÷ time	a = Δv ÷ t	a (m/s²), Δv (m/s), t (s)
(final velocity)² − (initial velocity)² = 2 × acceleration × distance	v² − u² = 2 a s	v, u (m/s), a (m/s²), s (m)

Waves & density

In words	Symbols	Quantities & units
wave speed = frequency × wavelength	v = f λ	v (m/s), f (Hz), λ (m)
wave speed = distance ÷ time	v = s ÷ t	v (m/s), s (m), t (s)
density = mass ÷ volume	ρ = m ÷ V	ρ (kg/m³), m (kg), V (m³)

Given vs recall: Equations you usually have to RECALL (not given): Eₖ=½mv², Eₚ=mgh, W=mg, W=Fs, P=E/t, Q=It, V=IR, P=VI, E=Pt, ρ=m/V, F=ma, a=Δv/t, v=fλ, F=ke, momentum p=mv. Equations usually PROVIDED on the sheet include the ones with squared or less-common terms (e.g. Eₑ=½ke², P=I²R, E=QV, ΔE=mcΔθ, v²−u²=2as). Always confirm against the current AQA equation sheet for your series.

Exam tip: Write the equation, substitute the numbers, then rearrange — and always convert units first (kW→W, minutes→seconds, cm→m).

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