⚛︎ Physics Formula Searcher

Physics Formula Sheet

A complete, free physics formula sheet — all 174 formulas organized by topic. Use the interactive searcher to find a formula by any variable, solve for any unknown, and convert units.

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Kinematics

Average velocityv = Δx / Δt
Average accelerationa = Δv / Δt
Velocity (constant a)v = u + a·t
Displacement (suvat)s = u·t + ½·a·t²
Velocity² (suvat)v² = u² + 2·a·s
Displacement (avg velocity)s = ½·(u + v)·t
Projectile rangeR = (v²·sin2θ) / g
Position (general)x = x₀ + v₀·t + ½·a·t²
Average speedv̄ = d / t
Relative velocityv_AB = v_A − v_B
Projectile time of flightt = 2·v·sinθ / g
Projectile max heightH = v²·sin²θ / (2·g)
Free fall velocityv = g·t
Free fall distanceh = ½·g·t²
Jerkj = da / dt

Dynamics & Forces

Newton's second lawF = m·a
WeightW = m·g
Friction forcef = μ·N
Hooke's lawF = -k·x
Centripetal forceF = m·v² / r
Centripetal accelerationa = v² / r
ImpulseJ = F·Δt = Δp
Tension (Atwood)T = 2·m₁·m₂·g / (m₁+m₂)
Inclined plane (parallel)F = m·g·sinθ
Inclined plane (normal)N = m·g·cosθ
Static friction (max)f_s = μ_s·N
Drag forceF_d = ½·ρ·v²·C_d·A
Terminal velocityv_t = √(2·m·g / (ρ·A·C_d))
Spring force constantk = F / x
Banked curve angletanθ = v² / (r·g)

Momentum & Impulse

Linear momentump = m·v
Angular momentumL = I·ω
Conservation of momentumm₁·u₁ + m₂·u₂ = m₁·v₁ + m₂·v₂
Elastic collision (1D)v₁ = ((m₁−m₂)·u₁ + 2·m₂·u₂)/(m₁+m₂)
Coefficient of restitutione = (v₂−v₁)/(u₁−u₂)
Center of massx_cm = Σ(mᵢ·xᵢ) / Σmᵢ
Rocket equationΔv = v_e·ln(m₀/m_f)
Angular impulseΔL = τ·Δt

Energy, Work & Power

Work doneW = F·d·cosθ
Kinetic energyKE = ½·m·v²
Gravitational PEPE = m·g·h
Elastic PEPE = ½·k·x²
PowerP = W / t
Power (force·velocity)P = F·v
Efficiencyη = E_out / E_in
Work–energy theoremW = ΔKE
Power (average)P̄ = ΔE / Δt
Mechanical energyE = KE + PE
Gravitational PE (orbital)E = −G·M·m / (2·r)

Rotational Motion

Torqueτ = r·F·sinθ
Angular velocityω = θ / t
Rotational KEKE = ½·I·ω²
Angular accelerationα = Δω / Δt
Rotational Newton's 2nd lawτ = I·α
Moment of inertia (point)I = m·r²
Moment of inertia (disk)I = ½·m·r²
Moment of inertia (rod, center)I = (1/12)·m·L²
Tangential velocityv = r·ω
Tangential accelerationa_t = r·α
Angular displacementθ = ω₀·t + ½·α·t²
Rolling kinetic energyKE = ½·m·v² + ½·I·ω²

Gravitation

Newton's gravitationF = G·m₁·m₂ / r²
Gravitational fieldg = G·M / r²
Gravitational PE (general)U = −G·m₁·m₂ / r
Orbital velocityv = √(G·M / r)
Escape velocityv_e = √(2·G·M / r)
Kepler's third lawT² = (4π²/G·M)·r³
Gravitational potentialV = −G·M / r
Orbital periodT = 2π·√(r³ / (G·M))

Waves & SHM

Wave speedv = f·λ
Period & frequencyT = 1 / f
SHM displacementx = A·cos(ω·t)
Pendulum periodT = 2π·√(L / g)
SHM velocityv = −A·ω·sin(ω·t)
SHM accelerationa = −ω²·x
SHM max velocityv_max = A·ω
Mass-spring periodT = 2π·√(m / k)
Angular frequencyω = 2π·f
Wave equation (number)k = 2π / λ
Doppler effect (sound)f' = f·(v ± v_o)/(v ∓ v_s)
Standing wave frequencyf_n = n·v / (2·L)
Speed of wave on stringv = √(T / μ)
IntensityI = P / A
Sound intensity levelβ = 10·log(I / I₀)
Beat frequencyf_beat = |f₁ − f₂|

Electricity & Magnetism

Ohm's lawV = I·R
Electrical powerP = V·I
Electrical energyE = V·I·t
ChargeQ = I·t
Coulomb's lawF = k·q₁·q₂ / r²
CapacitanceC = Q / V
ResistivityR = ρ·L / A
Magnetic force on wireF = B·I·L
Force on moving chargeF = q·v·B
Resistors in seriesR_eq = R₁ + R₂ + …
Resistors in parallel1/R_eq = 1/R₁ + 1/R₂ + …
Capacitors in parallelC_eq = C₁ + C₂ + …
Capacitors in series1/C_eq = 1/C₁ + 1/C₂ + …
Power (I²R)P = I²·R
Power (V²/R)P = V² / R
Electric field (point charge)E = k·q / r²
Electric field (force)E = F / q
Electric potential energyU = k·q₁·q₂ / r
Electric potentialV = k·q / r
Capacitor energyE = ½·C·V²
Parallel plate capacitorC = ε₀·A / d
Drift velocityI = n·A·q·v_d
Magnetic fluxΦ = B·A·cosθ
Faraday's lawε = −N·dΦ/dt
Solenoid fieldB = μ₀·n·I
Field around wireB = μ₀·I / (2π·r)
Transformer ratioV_s/V_p = N_s/N_p

Thermodynamics

Heat energyQ = m·c·ΔT
Latent heatQ = m·L
Ideal gas lawP·V = n·R·T
PressureP = F / A
Densityρ = m / V
First law of thermodynamicsΔU = Q − W
Thermal expansion (linear)ΔL = α·L₀·ΔT
Thermal expansion (volume)ΔV = β·V₀·ΔT
Heat conductionQ/t = k·A·ΔT / L
Carnot efficiencyη = 1 − T_c / T_h
Entropy changeΔS = Q / T
Average KE of gasKE = (3/2)·k_B·T
RMS molecular speedv_rms = √(3·k_B·T / m)
Work in isobaric processW = P·ΔV
Stefan–Boltzmann lawP = σ·A·e·T⁴
Wien's displacement lawλ_max = b / T

Modern Physics & Relativity

Mass–energyE = m·c²
Photon energyE = h·f
de Broglie wavelengthλ = h / p
Photoelectric effectE = h·f − φ
Relativistic momentump = γ·m·v
Lorentz factorγ = 1 / √(1 − v²/c²)
Time dilationΔt = γ·Δt₀
Length contractionL = L₀ / γ
Relativistic energyE = γ·m·c²
Energy–momentum relationE² = (p·c)² + (m·c²)²
Heisenberg uncertaintyΔx·Δp ≥ ħ / 2
Bohr radius / energyE_n = −13.6 eV / n²
Rydberg formula1/λ = R·(1/n₁² − 1/n₂²)
Compton wavelength shiftΔλ = (h/m_e·c)·(1 − cosθ)

Optics

Snell's lawn₁·sinθ₁ = n₂·sinθ₂
Index of refractionn = c / v
Thin lens equation1/f = 1/d_o + 1/d_i
MagnificationM = −d_i / d_o = h_i / h_o
Critical anglesinθ_c = n₂ / n₁
Mirror equation1/f = 1/d_o + 1/d_i
Double slit (maxima)d·sinθ = m·λ
Diffraction gratingd·sinθ = n·λ
Lens powerP = 1 / f

Fluid Mechanics

Pressure in fluidP = ρ·g·h
Buoyant forceF_b = ρ·g·V
Continuity equationA₁·v₁ = A₂·v₂
Bernoulli's equationP + ½·ρ·v² + ρ·g·h = const
Flow rateQ = A·v
Viscous drag (Stokes)F = 6π·η·r·v
Reynolds numberRe = ρ·v·L / η

AC Circuits

RMS voltageV_rms = V₀ / √2
RMS currentI_rms = I₀ / √2
Capacitive reactanceX_C = 1 / (2π·f·C)
Inductive reactanceX_L = 2π·f·L
Impedance (RLC)Z = √(R² + (X_L − X_C)²)
Resonant frequencyf₀ = 1 / (2π·√(L·C))
Inductor energyE = ½·L·I²

Nuclear Physics

Radioactive decayN = N₀·e^(−λ·t)
Half-lifet½ = ln2 / λ
ActivityA = λ·N
Mass defect energyE = Δm·c²
Binding energy per nucleonBE/A = (Δm·c²) / A

Astrophysics

Schwarzschild radiusr_s = 2·G·M / c²
Hubble's lawv = H₀·d
Luminosity (inverse square)b = L / (4π·d²)
Stellar luminosityL = 4π·R²·σ·T⁴