AP Physics 2 Formula Sheet — Every Equation You Need (2026)
The AP Physics 2 exam provides a formula sheet during the test — but knowing what's on it and how to use each equation is what separates a 3 from a 5.
What's on the Official AP Physics 2 Formula Sheet
College Board provides the same reference sheet for AP Physics 2 as for AP Physics 1, plus additional equations for the topics unique to Physics 2. You get this sheet for both the multiple choice and free response sections.
The sheet includes equations — it does not explain when to use them. That knowledge is entirely on you.
Fluids
| Equation | Variables | When to use |
|---|---|---|
| ρ = m/V | ρ = density, m = mass, V = volume | Finding density or mass of a fluid |
| P = P₀ + ρgh | P = pressure, P₀ = surface pressure, h = depth | Pressure at depth in a static fluid |
| F_b = ρVg | F_b = buoyant force, ρ = fluid density, V = submerged volume | Archimedes' principle |
| A₁v₁ = A₂v₂ | A = cross-sectional area, v = fluid velocity | Continuity equation (incompressible flow) |
| P + ½ρv² + ρgh = constant | Bernoulli's equation | Energy conservation in fluid flow |
Key concept: Bernoulli's equation is just conservation of energy per unit volume. High velocity = low pressure (venturi effect, airplane lift).
Thermodynamics
| Equation | Variables | When to use |
|---|---|---|
| PV = nRT | P = pressure, V = volume, n = moles, R = 8.31 J/mol·K, T = temperature (K) | Ideal gas law |
| K_avg = (3/2)k_BT | K_avg = avg kinetic energy per molecule, k_B = Boltzmann constant | Relating temperature to molecular KE |
| ΔU = Q + W | ΔU = change in internal energy, Q = heat added, W = work done on gas | First law of thermodynamics |
| e = W_net/Q_H | e = efficiency, Q_H = heat from hot reservoir | Heat engine efficiency |
| e_Carnot = 1 - T_C/T_H | T_C = cold temp, T_H = hot temp (in Kelvin) | Maximum possible efficiency |
Key concept: For the Carnot efficiency equation, temperatures must be in Kelvin. A common mistake is using Celsius.
Electricity and Magnetism
Electric Force and Field
| Equation | Variables | When to use |
|---|---|---|
| F_E = kq₁q₂/r² | k = 8.99×10⁹ N·m²/C², q = charges, r = distance | Coulomb's law |
| E = F_E/q = kq/r² | E = electric field magnitude | Field from a point charge |
| U_E = kq₁q₂/r | U_E = electric potential energy | PE between two point charges |
| V = kq/r | V = electric potential | Potential from a point charge |
| E = -ΔV/Δr | Relationship between E field and potential | |
| C = Q/V | C = capacitance, Q = charge | Definition of capacitance |
| C = κε₀A/d | κ = dielectric constant, A = plate area, d = separation | Parallel plate capacitor |
| U_C = ½QV = ½CV² | U_C = energy stored | Energy stored in capacitor |
Circuits
| Equation | Variables | When to use |
|---|---|---|
| I = ΔQ/Δt | I = current, Q = charge | Definition of current |
| R = ρL/A | ρ = resistivity, L = length, A = area | Resistance of a conductor |
| V = IR | Ohm's law | |
| P = IV = I²R = V²/R | P = power | Power dissipated in a resistor |
| Series: R_eq = R₁ + R₂ + ... | Resistors in series | |
| Parallel: 1/R_eq = 1/R₁ + 1/R₂ + ... | Resistors in parallel |
Magnetism
| Equation | Variables | When to use |
|---|---|---|
| F = qv × B | F = magnetic force, q = charge, v = velocity, B = field | Force on moving charge |
| F = IL × B | I = current, L = length | Force on current-carrying wire |
| Φ_B = B·A·cosθ | Φ_B = magnetic flux | Flux through a surface |
| ε = -ΔΦ_B/Δt | ε = induced EMF | Faraday's law |
Optics
| Equation | Variables | When to use |
|---|---|---|
| n = c/v | n = index of refraction, c = speed of light, v = speed in medium | Snell's law setup |
| n₁sinθ₁ = n₂sinθ₂ | Snell's law | Refraction at interface |
| sinθ_c = n₂/n₁ | θ_c = critical angle | Total internal reflection |
| 1/d_o + 1/d_i = 1/f | d_o = object distance, d_i = image distance, f = focal length | Thin lens/mirror equation |
| M = -d_i/d_o | M = magnification | Image size relative to object |
Key concept: For mirrors, f = R/2 where R is radius of curvature. Converging = positive f, diverging = negative f.
Modern Physics
| Equation | Variables | When to use |
|---|---|---|
| E = hf | E = photon energy, h = 6.626×10⁻³⁴ J·s, f = frequency | Energy of a photon |
| E = hc/λ | λ = wavelength | Same, using wavelength |
| K_max = hf - φ | K_max = max KE of ejected electron, φ = work function | Photoelectric effect |
| E² = (pc)² + (mc²)² | E = total energy, p = momentum, m = rest mass | Relativistic energy |
| E = mc² | Special case when p = 0 | Mass-energy equivalence |
| λ = h/p | de Broglie wavelength | Wave nature of matter |
What's NOT on the Formula Sheet (Memorize These)
These equations are commonly needed but not provided:
- Snell's law — actually IS provided, but many students miss it
- Direction of induced current (Lenz's law) — you must know the concept
- Electric field lines go from + to −, perpendicular to equipotentials
- Right-hand rule for magnetic force direction — entirely conceptual
- Half-life: t₁/₂ = 0.693/λ — not on the sheet, must memorize
- Nuclear decay rules — alpha loses 2 protons/2 neutrons, beta emits electron
How to Use the Formula Sheet Strategically
Before the exam: Go through every equation on the official sheet. Write out in your own words what each variable means and when to use it.
During multiple choice: Don't flip to the formula sheet for equations you know — it wastes time. Use it only when stuck.
During FRQ: Always write the equation first, then substitute numbers. You earn points for correct setup even with arithmetic errors.
Units are a built-in check: If your units don't work out to what the question asks for, your equation is wrong.
AP Physics 2 Score Calculator
Use our AP Physics 2 Score Calculator to see how many points you need on each section to hit your target score.
AP Physics 2 score cutoffs (2026):
| AP Score | Composite Range |
|---|---|
| 5 | 115–150 |
| 4 | 85–114 |
| 3 | 55–84 |
| 2 | 35–54 |
| 1 | 0–34 |