Kinematics
v final velocity, u initial velocity, a acceleration, t time, s displacement.
v = u + at s = ut + ½ at² v² = u² + 2as s = ½ (u + v)t a = Δv / Δt Edexcel International A Level XPH11/YPH11
🔭 Edexcel International A Level Physics Formula Sheet 2025
Mechanics, wave, electricity, fields and quantum equations aligned to the Edexcel XPH11/YPH11 syllabus, ready for Units 1–6 practice.
Mechanics Electricity Fields Quantum
Core Physics Equations with Application Notes
Use this organised sheet to recall definitions, constants and relationships quickly. Pair each formula with the conditions of use so you can explain assumptions clearly in structured questions.
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Mechanics & materials constants at a glance
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Wave and quantum relationships grouped
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Electric circuits and field equations
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Thermal & nuclear data with context
Mechanics & Materials
Dynamics
F net force, m mass, p momentum, Δp change in momentum, t time interval.
Newton's Second Law
F = ma Momentum
p = mv Impulse
Impulse = Ft = Δp Force as rate of change of momentum
F = dp/dt Work, Energy & Power
F applied force, d displacement, θ angle between force and motion, m mass, v speed, g gravitational field strength, k spring constant, x extension.
Work = Fd cos θ KE = ½ mv² GPE = mgh Elastic PE = ½ kx² Power = Work / Time = Fv Circular Motion
r radius, T period, ω angular speed, v tangential speed, m mass, a_c centripetal acceleration.
v = 2πr / T = ωr a_c = v² / r = ω²r F_c = mv² / r = mω²r Simple Harmonic Motion (SHM)
a acceleration towards equilibrium, ω angular frequency, x displacement, A amplitude, T period, m mass, k spring constant, l pendulum length.
a = −ω²x x = A sin(ωt) or A cos(ωt) v = ±ω √(A² − x²) T = 2π √(m/k) (mass-spring) T = 2π √(l/g) (simple pendulum) Stress & Strain
Stress uses force F over cross-sectional area A; strain compares extension Δl to original length l; E is Young modulus.
Stress = Force / Area Strain = Extension / Original length Young modulus, E = Stress / Strain Energy per unit volume = ½ × Stress × Strain Electricity & Magnetism
Electrical Quantities
I current, Q charge, t time, V potential difference, W energy transferred, R resistance, ρ resistivity, A cross-sectional area, l conductor length, P power.
Current, I = ΔQ / Δt Voltage, V = W / Q Resistance, R = V / I Resistivity, ρ = RA / l Power, P = VI = I²R = V²/R Series & Parallel
R_series = R₁ + R₂ + ⋯ 1 / R_parallel = 1/R₁ + 1/R₂ + ⋯ V_series divides by resistance ratios, I_parallel splits inversely. Charge & Capacitance
Q charge stored, C capacitance, V potential difference across plates.
Q = CV Energy stored, W = ½ CV² = ½ QV = Q²/(2C) Capacitors in parallel: C_total = C₁ + C₂ + ⋯ Capacitors in series: 1/C_total = 1/C₁ + 1/C₂ + ⋯ Magnetic Fields
B magnetic flux density, I current, L conductor length in field, Q charge, v particle speed, Φ magnetic flux, N coil turns, θ angle relative to field.
Magnetic force on conductor: F = BIL sin θ Magnetic force on moving charge: F = BQv sin θ Magnetic flux, Φ = BA cos θ Flux linkage, NΦ Faraday’s law: Induced emf = −N dΦ/dt Lenz’s law: Direction opposes change causing it. Alternating Current (AC)
I₀ peak current, V₀ peak voltage, I_rms and V_rms root-mean-square values.
I_rms = I₀ / √2 V_rms = V₀ / √2 Average power, P = V_rms I_rms Fields & Potentials
Gravitational Field
G gravitational constant, M source mass, m test mass, r separation, φ potential, E_p potential energy.
Force: F = GMm / r² Field strength: g = GM / r² Potential: φ = −GM / r Potential energy: E_p = −GMm / r Electric Field
k = 1/(4πϵ₀), Q source charge, q test charge, r separation, E field strength, V potential difference, d plate separation.
Force: F = kQq / r² (k = 1/4πϵ₀) Field strength: E = F/q = kQ / r² Potential: V = kQ / r Uniform field: E = V/d Potential Gradient
V potential, r radial distance; negative gradient gives field strength.
Field strength = −dV/dr Escape Velocity
v_e escape speed, G gravitational constant, M planetary mass, r distance from centre.
v_e = √(2GM / r) Kepler’s Third Law (Circular Orbit)
T orbital period, r orbital radius, M central mass.
T² = (4π² / GM) r³ Waves, Optics & Quantum
Wave Relationships
v wave speed, f frequency, λ wavelength, ω angular frequency.
v = fλ Angular frequency, ω = 2πf Phase difference = (path difference / λ) × 2π Interference & Diffraction
a slit separation, d grating spacing, n order number, μ refractive index, t film thickness, θ diffraction angle, r refracted angle.
Double-slit: a sin θ = nλ Diffraction grating: d sin θ = nλ Thin film constructive: 2μt cos r = nλ Optics
f focal length, v image distance, u object distance, m magnification.
Lens equation: 1/f = 1/v + 1/u Magnification: m = v/u = image height / object height Photoelectric Effect
h Planck constant, f incident frequency, φ work function, m electron mass, v_max maximum electron speed, e electron charge, V₀ stopping potential.
Photon energy: E = hf = hc/λ Einstein’s equation: hf = φ + ½ mv_max² Stopping potential: eV₀ = ½ mv_max² de Broglie Wavelength
λ wavelength, h Planck constant, p momentum, m particle mass, v speed.
λ = h / p = h / (mv) Thermal, Nuclear & Quantum Statistics
Thermal Physics
Q thermal energy, m mass, c specific heat capacity, Δθ temperature change, L specific latent heat, p pressure, V volume, n moles, R gas constant, N molecules, k Boltzmann constant, T temperature.
Specific heat capacity: Q = mcΔθ Specific latent heat: Q = mL Ideal gas law: pV = nRT = NkT Pressure from molecular model: pV = 1/3 Nm c² Gas Laws
p pressure, V volume, T absolute temperature (in kelvin).
Boyle’s: p ∝ 1/V (T constant) Charles’: V ∝ T (p constant) Pressure law: p ∝ T (V constant) Radioactivity
A activity, λ decay constant, N number of undecayed nuclei, t time, N₀ initial nuclei count.
Activity: A = λN Decay law: N = N₀ e^{−λt} Half-life: T½ = ln 2 / λ Activity ratio: A/A₀ = e^{−λt} Binding Energy
Δm is mass defect (nucleons − actual nucleus mass).
E_b = (Δm)c² Fermi-Dirac / Bose-Einstein (syllabus emphasis)
Be able to identify classical vs quantum statistics qualitatively; no formula derivations required.
How to Use This Formula Sheet
Boost your Cambridge exam confidence with these proven study strategies from our tutoring experts.
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State Assumptions
Before using formulas, note key assumptions (uniform field, negligible air resistance, ideal gas) to gain method and explanation marks.
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Track Units Carefully
Convert to SI units (m, kg, s) before substitution. Include unit in the final answer to avoid losing accuracy marks.
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Sketch Diagrams Fast
Draw quick field, circuit or wave diagrams to confirm direction and sign conventions before calculating.
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Link Maths to Physics
When using calculus or logarithms (e.g., decay, SHM), explain the physical behaviour to earn reasoning marks.
Accelerate Your A Level Physics Mastery
Work through challenging Edexcel-style problems with tutors who highlight where to apply each equation and how to present full-credit explanations.
Formulas follow Edexcel International AS & A Level Physics (XPH11/YPH11) data booklet conventions.
Carry constants: h = 6.63×10⁻³⁴ J s, e = 1.60×10⁻¹⁹ C, c = 3.00×10⁸ m s⁻¹, R = 8.31 J mol⁻¹ K⁻¹.