AP Physics 2 Last-Minute Review (Night Before)

title: "AP Physics 2 Last-Minute Review (Night Before)" description: "The night-before AP Physics 2 checklist: essential formulas, common traps, diagram tips, and morning advice. Skim in 45 minutes, then sleep." date: "2026-01-15" examDate: "May AP Exam" topics:

• Formula Reference
• Common Traps
• Diagram Tips
• Score Boundaries

The exam is tomorrow. Spend 30–45 minutes skimming this page, then sleep for 8 hours. Your brain consolidates procedural memory during sleep.

Essential formulas by unit

Fluids

$P = P_0 + \rho g h \quad \text{(pressure at depth)}$ $F_b = \rho_{\text{fluid}} V_{\text{displaced}} g \quad \text{(buoyant force)}$ $A_1 v_1 = A_2 v_2 \quad \text{(continuity)}$

Thermodynamics

$PV = nRT \quad \text{(ideal gas law, } R = 8.31 \, \text{J/(mol·K))}$ $\Delta U = Q + W \quad \text{(first law, } W = \text{work on gas)}$ $W = P \Delta V \quad \text{(isobaric process)}$ $\eta = 1 - \frac{Q_c}{Q_h} \quad \text{(heat engine efficiency)}$

Electric Force & Potential

$F = k \frac{q_1 q_2}{r^2} \quad \text{(Coulomb's law, } k = 9 \times 10^9 \, \text{N·m}^2\text{/C}^2 \text{)}$ $E = k \frac{Q}{r^2} \quad \text{(electric field)}$ $V = k \frac{Q}{r} \quad \text{(electric potential)}$ $W = q \Delta V \quad \text{(work on charge)}$

Circuits

$V = IR \quad \text{(Ohm's law)}$ $R_{\text{series}} = \sum R \quad \text{(series resistors)}$ $\frac{1}{R_{\text{parallel}}} = \sum \frac{1}{R} \quad \text{(parallel resistors)}$ $P = I^2 R = \frac{V^2}{R} = IV \quad \text{(power)}$

Magnetism & Induction

$F = qvB \sin\theta \quad \text{(Lorentz force)}$ $F = BIL \sin\theta \quad \text{(force on current-carrying wire)}$ $\Phi_B = BA \cos\theta \quad \text{(magnetic flux)}$ $\mathcal{E} = -\frac{d\Phi_B}{dt} \quad \text{(Faraday's law)}$

Optics

$n_1 \sin\theta_1 = n_2 \sin\theta_2 \quad \text{(Snell's law)}$ $\frac{1}{f} = \frac{1}{d_o} + \frac{1}{d_i} \quad \text{(lens/mirror equation)}$ $m = -\frac{d_i}{d_o} \quad \text{(magnification)}$ $\text{Bright fringes: path difference} = m\lambda \quad \text{(double-slit)}$

Modern Physics

$E = hf \quad \text{(photon energy)}$ $hf = KE_{\text{max}} + \phi \quad \text{(photoelectric effect)}$ $E = mc^2 \quad \text{(mass-energy equivalence)}$ $N(t) = N_0 \left(\frac{1}{2}\right)^{t/t_{1/2}} \quad \text{(radioactive decay)}$

Top 15 traps that cost real points

| # | Trap | Fix | |---|---|---| | 1 | Work sign in thermo | Compression: $W > 0$ (on gas). Expansion: $W < 0$ (by gas). Write out which. | | 2 | Series vs parallel | Series: $R = \sum R$, voltage divides. Parallel: $\frac{1}{R} = \sum \frac{1}{R}$, current divides. Redraw simplified first. | | 3 | Lenz's law direction | Induced current opposes the change, not the field. If flux ↑, induced field ↓. | | 4 | Lens equation sign | Real: $d > 0$. Virtual: $d < 0$. Converging: $f > 0$. Diverging: $f < 0$. | | 5 | Lorentz force is perpendicular | $\vec{F} = q\vec{v} \times \vec{B}$ always ⊥ to $v$. Right-hand rule: fingers = $v$, curl = $B$, thumb = $F$. | | 6 | Photoelectric threshold | Photon energy must exceed work function. If $hf < \phi$, zero electrons emitted. | | 7 | Snell's law at normal incidence | $\theta = 0°$ → $\sin(0°) = 0$ → no bending at all. | | 8 | Buoyancy = displaced volume | $F_b$ depends on fluid volume displaced, not total object volume. | | 9 | Potential vs potential energy | $V$ = energy per charge (J/C). $U = qV$ = total energy. Don't confuse. | | 10 | Magnification sign | Negative $m$ = inverted. Positive = upright. Check your diagram matches. | | 11 | Capacitor in series | $\frac{1}{C_{\text{tot}}} = \frac{1}{C_1} + \frac{1}{C_2}$ (opposite of resistors). | | 12 | Half-life counting | After 1 half-life: $N = N_0/2$. After 2: $N = N_0/4$. Count carefully. | | 13 | Forgetting $k$ in Coulomb | $F = k \frac{q_1 q_2}{r^2}$. Missing $k$ → off by $9 \times 10^9$. | | 14 | Diagram labels | Rubrics give points for drawing itself. Label all forces, currents, rays. | | 15 | Units missing | Final answer without units = partial or no credit. Always write (N, J, V, A, etc.). |

Diagram quick rules

Circuits

✓ Do: Nodes (•), battery polarity, current arrows, $R$ labels, simplified equivalent. ✗ Don't: Ambiguous junctions. Unlabeled components.

Ray diagrams

✓ Do: 3-ray method, focal points, optical axis, object left/image right (real) or left (virtual). ✗ Don't: Rays that don't meet at image. Forgetting to mark $F$.

PV diagrams

✓ Do: Label points, identify process type, shade area under curve (= work). ✗ Don't: Forget to show direction (arrow). Mislabel isothermal as straight line.

Free body diagrams

✓ Do: All forces, dot for object, labels ($F_b$, $F_g$, $F_{\text{applied}}$). ✗ Don't: Include forces that don't act. Skip direction arrows.

Score boundaries (recent years)

Out of 300 points (150 MCQ + 150 FRQ):

| Score | Approximate % | Points | |---|---|---| | 5 | 70–100% | 210+ | | 4 | 57–69% | 171–209 | | 3 | 44–56% | 132–170 | | 2 | 31–43% | 93–131 | | 1 | <31% | <93 |

You only need ~210 points (70%) for a 5. You can skip ~4–5 hard MCQs and lose points on 1–2 FRQs and still earn the top score. Don't panic.

Calculator tips

• Show setup first: Always write the equation before the decimal. Rubrics award points for method, not just answer.
• Numerical solve: Use nSolve or graph-intersect on messy algebra, but show your setup.
• Scientific notation: Watch tiny exponents (e.g., $10^{-19}$ on charges). One order-of-magnitude error fails the whole problem.
• Unit check: Before submitting, ask "does this unit make sense?" (Force in N, not J; Energy in J, not N).

Morning-of checklist

• ☐ 8 hours of sleep (non-negotiable).
• ☐ Real breakfast: protein + complex carbs (not just sugar).
• ☐ 2 sharpened #2 pencils, blue/black pen.
• ☐ Approved calculator + spare batteries. Test beforehand.
• ☐ Watch (no alarm) if room clock is not visible.
• ☐ AP ID label sheet + photo ID.
• ☐ Water bottle, light snack (fruit, granola bar).
• ☐ Arrive 30 minutes early. No rushing.

During the MCQ section (first 50 questions, 90 min)

1. Skim all 50 first (2 min). Mark scary ones.
2. Do confident questions first (2–3 min each). Build momentum.
3. Flag & skip anything taking >3 min. Return in final 5 min.
4. Last 5 minutes: return to flagged. Use process of elimination (cross out violations of physics).

💡 Elimination trick: Cross out answers that violate a principle (e.g., negative mass, $F$ without acceleration). Usually leaves 2–3 choices.

During the FRQ section (6 FRQs, 90 min)

1. Read all 6 first (3 min). Pick the 3 you're most confident on.
2. Do those 3 first (12 min each = 36 min). Lock in easy points.
3. Attempt harder 3 (6 min each = 18 min). Partial credit adds up—set up equation, define variables, show work.
4. Do NOT leave blank. A wrong attempt with reasoning earns 1–2 points. Blank = 0.

⚠️ FRQ rubric: Typically 1 pt setup, 1 pt equation, 1 pt calculation, 1 pt reasoning. Hit setup + equation = 50% already.

One last thing

You've prepped. Your formulas are embedded. Your FRQ strategy is solid. The exam will throw curveballs, but they always stick to the CED topics. Trust your work. Show up rested, read carefully, and remember that the rubric wants to give you points—write clearly enough that it can.

Get 8 hours of sleep tonight.

You've got this. 🎯

Need a final confidence boost? Review the FRQ practice guide → or redo one mock section from the 7-day plan →.