1. Fluid Mechanics
$$P = \frac{F}{A}$$
$$P = P_0 + \rho gh$$
$$F_b = \rho g V$$
When it appears:
- Pressure in fluids
- Buoyancy problems
👉 Focus on depth and density relationships
2. Thermodynamics
$$Q = mc\Delta T$$
$$\Delta U = Q – W$$
When it appears:
- Heat transfer
- Energy conservation in thermal systems
3. Ideal Gas Law
$$PV = nRT$$
When it appears:
- Gas behavior problems
- Changes in pressure, volume, temperature
4. Electric Force and Field
$$F = k \frac{q_1 q_2}{r^2}$$
$$E = \frac{F}{q}$$
When it appears:
- Point charges
- Field interactions
5. Electric Potential
$$V = k \frac{q}{r}$$
$$\Delta V = – \int E \, dr$$
When it appears:
- Energy in electric systems
- Relation between field and potential
6. Capacitance
$$C = \frac{Q}{V}$$
$$U = \frac{1}{2}CV^2$$
When it appears:
- Energy storage
- Capacitor problems
7. Electric Circuits
$$P = IV = I^2R = \frac{V^2}{R}$$
When it appears:
- Circuit analysis
- Power calculations
8. Waves and Optics
$$v = f \lambda$$
$$n = \frac{c}{v}$$
When it appears:
- Wave behavior
- Refraction
9. Snell’s Law
$$n_1 \sin \theta_1 = n_2 \sin \theta_2$$
When it appears:
- Light refraction
- Boundary problems
10. Mirror and Lens Equation
$$\frac{1}{f} = \frac{1}{d_o} + \frac{1}{d_i}$$
When it appears:
- Image formation
- Optics FRQs
11. Magnification
$$M = \frac{h_i}{h_o} = -\frac{d_i}{d_o}$$
When it appears:
- Image size and orientation
12. Quantum and Atomic Physics
$$E = hf$$
$$E = \frac{hc}{\lambda}$$
When it appears:
- Photoelectric effect
- Photon energy problems
Final Strategy for the Exam
- Focus on:
- Circuits
- Fluids
- Optics
- Always:
- Track units carefully
- Interpret physical meaning
- Use diagrams
Pro Tip
Top scorers:
✔ Understand concepts over memorization
✔ Connect equations to real-world systems
✔ Explain reasoning clearly in FRQs
This guide helps you quickly decide which formula to apply under exam pressure.