AP Physics 2 Formula Sheet Cheat Sheet

Key Facts

• Fluid pressure is given by $P = \frac{F}{A}$, and the pressure at depth $h$ in a fluid is $P = P_0 + \rho gh$.
• The buoyant force on an object equals the weight of displaced fluid, so $F_B = \rho_{\text{fluid}} V_{\text{disp}} g$.
• For ideal fluid flow, the continuity equation is $A_1v_1 = A_2v_2$ and Bernoulli's equation is $P + \frac{1}{2}\rho v^2 + \rho gy = \text{constant}$.
• The ideal gas law is $PV = nRT = Nk_BT$, and the average translational kinetic energy per molecule is $K_{\text{avg}} = \frac{3}{2}k_BT$.
• The first law of thermodynamics is $\Delta U = Q + W_{\text{on}}$, where $Q$ is heat added to the system and $W_{\text{on}}$ is work done on the system.
• Coulomb's law is $F = k\frac{|q_1q_2|}{r^2}$, and the electric field from a point charge is $E = k\frac{|q|}{r^2}$.
• Capacitance is $C = \frac{Q}{\Delta V}$, and the energy stored in a capacitor is $U_C = \frac{1}{2}C(\Delta V)^2$.
• Photon energy is $E = hf = \frac{hc}{\lambda}$, and mass-energy equivalence is $E = mc^2$.

Vocabulary

Pressure

Pressure is the force applied perpendicular to a surface per unit area, calculated by $P = \frac{F}{A}$.

Buoyant Force

Buoyant force is the upward force a fluid exerts on an object equal to the weight of the displaced fluid.

Electric Field

An electric field is the force per unit positive test charge at a location, defined by $E = \frac{F}{q}$.

Capacitance

Capacitance is a measure of how much charge a device stores per potential difference, given by $C = \frac{Q}{\Delta V}$.

Magnetic Flux

Magnetic flux measures how much magnetic field passes through an area and is calculated by $\Phi_B = BA\cos\theta$.

Photon

A photon is a packet of electromagnetic energy with energy $E = hf$.