141 lines
6.1 KiB
Plaintext
141 lines
6.1 KiB
Plaintext
== AP PHYSICS 1 UNIT 1: KINEMATICS ==
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Scalars vs vectors: magnitude only vs magnitude+direction
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1D motion: track position, velocity, acceleration separately
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Slope of position-time = velocity
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Slope of velocity-time = acceleration
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Area under velocity-time = displacement
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Average velocity = total displacement / total time
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Constant acceleration: use kinematic equations
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Instantaneous velocity = slope of position-time at point
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Reference frames: relative velocity
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Vectors in 2D: add/subtract components, resolve angles
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Projectile: horizontal = constant velocity, vertical = constant acceleration
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Range = v_x*t, max height = v_y^2/(2g)
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Symmetry: time up = time down (launch/land same height)
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Acceleration always points down = g
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Equal time intervals: equal vertical displacement increments
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== AP PHYSICS 1 UNIT 2: FORCE AND TRANSLATIONAL DYNAMICS ==
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System: choose boundaries, internal forces cancel
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External forces cause system acceleration
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ΣF = ma (net force = mass x acceleration)
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Free-body diagram: ONLY external forces on chosen object
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Weight = mg (field force)
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Normal force: contact perpendicular, NOT always equal to weight
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Friction: kinetic = μ_k*F_N, static ≤ μ_s*F_N
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Friction opposes motion, direction opposite velocity
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Incline: resolve gravity into parallel (mg sin θ) and perpendicular (mg cos θ)
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Tension: pulls along string/rope, same throughout ideal rope
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Pulley: massless frictionless pulley transmits force unchanged
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Newton's 3rd Law: action-reaction pairs equal opposite different objects
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Mass vs weight: mass constant, weight depends on location
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Equilibrium: ΣF = 0, not necessarily zero velocity
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Terminal velocity: when drag = weight, a = 0, v constant
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== AP PHYSICS 1 UNIT 3: WORK, ENERGY, AND POWER ==
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Work done: W = F*d*cos(θ) where θ is angle between force and displacement
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Only force component parallel to displacement does work
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Negative work: force opposes motion (friction, air resistance)
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Work-energy theorem: net work = change in kinetic energy
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Kinetic energy: KE = 0.5*m*v^2
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Conservative force: work path independent (gravity, spring)
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Non-conservative force: work path dependent (friction)
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Gravitational PE: PE_g = m*g*Δh (only height change matters)
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Spring PE: PE_s = 0.5*k*x^2 where x is displacement from equilibrium
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Mechanical energy: E = KE + PE
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Conservation of energy: E_initial = E_final (if only conservative forces)
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Non-conservative work: W_nc = ΔKE + ΔPE
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Power: P = W/t (average) or P = F*v (instantaneous)
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Energy transfer via work
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Energy transfers between forms, never created/destroyed
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== AP PHYSICS 1 UNIT 4: LINEAR MOMENTUM AND COLLISIONS ==
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Momentum: p = m*v (vector quantity)
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Impulse: J = F_avg*Δt = Δp (change in momentum)
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Impulse-momentum theorem: impulse = momentum change
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Force-time graph area = impulse
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Center of mass: x_cm = Σ(m_i*x_i) / Σm_i
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v_cm = Σ(m_i*v_i) / Σm_i
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Conservation of momentum: Σp_initial = Σp_final (isolated system)
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External force = rate of change of momentum
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Elastic collision: KE conserved AND momentum conserved
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Inelastic collision: momentum conserved, KE NOT conserved
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Perfectly inelastic: objects stick together, max KE loss
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1D vs 2D: use components for 2D collisions
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Explosions: reverse of inelastic collision, momentum conserved
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Internal forces don't change center of mass motion
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== AP PHYSICS 1 UNIT 5: TORQUE AND ROTATIONAL DYNAMICS ==
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Torque: τ = r*F*sin(θ) = F_perp*r
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r is distance from pivot to force application point
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Lever arm: perpendicular distance from pivot to force line
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τ = I*α (rotational analog of F = ma)
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Moment of inertia: I = Σ(m_i*r_i^2)
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Parallel axis theorem: I = I_cm + M*d^2
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Rotational KE: KE_rot = 0.5*I*ω^2
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Angular momentum: L = I*ω
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Angular momentum conserved if no external torque
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Rotational work: W = τ*Δθ
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Rotational power: P = τ*ω
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Rolling without slipping: v = r*ω, a = r*α
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Static friction enables rolling
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Angular acceleration same for all points
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Angular velocity same for all points
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Angular momentum: L = m*v*r*sin(θ) for point mass
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Rotational inertia depends on mass distribution
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== AP PHYSICS 1 UNIT 6: ENERGY AND MOMENTUM OF ROTATING SYSTEMS ==
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Rotational systems: combine translational + rotational energy
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Rolling objects: total KE = KE_trans + KE_rot
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Solid sphere: I = 0.5*M*R^2
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Hollow sphere: I = 2/3*M*R^2
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Disk/cylinder: I = 0.5*M*R^2
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Hoop: I = M*R^2
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Angular impulse: J_ang = τ*Δt = ΔL
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Angular momentum conserved if Στ_ext = 0
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Collisions of rotating systems
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Rolling friction vs static friction (no slip = static)
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Angular momentum conservation in collisions
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Energy conservation includes rotational terms
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Angular momentum transfer between objects
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Rotational energy transfer via work
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== AP PHYSICS 1 UNIT 7: OSCILLATIONS ==
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Simple harmonic motion (SHM): restoring force F = -k*x
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Equilibrium position: net force = 0
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Amplitude: maximum displacement from equilibrium
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Period: time for one complete cycle
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Frequency: f = 1/T cycles per second
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Angular frequency: ω = 2πf
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Spring oscillator period: T_s = 2π*sqrt(m/k)
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Pendulum period: T_p = 2π*sqrt(L/g)
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Simple pendulum: small angles only (<15°)
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Period independent of mass (spring) or amplitude (small angles)
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Energy in SHM: E = 0.5*k*A^2 = 0.5*m*v_max^2
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PE_max = KE_max at equilibrium
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At extremes: v = 0, a = max, PE = max, KE = 0
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At center: a = 0, v = max, PE = min, KE = max
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Damped oscillation: energy loss to friction
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Forced oscillation: driving frequency
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Resonance: driving freq = natural freq
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Period vs frequency inverse relationship
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== AP PHYSICS 1 UNIT 8: FLUIDS ==
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Density: ρ = m/V (constant for incompressible)
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Pressure: P = F/A (force perpendicular to surface)
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Pressure increases with depth: P = P_0 + ρ*g*h
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Gauge pressure: P_gauge = ρ*g*h
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Atmospheric pressure: ~1 atm = 1.0E5 Pa = 101 kPa
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Pascal's principle: pressure change transmits equally
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Buoyant force: F_b = ρ_fluid*V_displaced*g
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Archimedes: buoyant force = weight of displaced fluid
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Object floats if ρ_object < ρ_fluid
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Floats submerged if ρ_object = ρ_fluid (neutral buoyancy)
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Sink if ρ_object > ρ_fluid
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Continuity equation: A_1*v_1 = A_2*v_2 (incompressible flow)
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Bernoulli: P_1 + 0.5*ρ*v_1^2 + ρ*g*h_1 = P_2 + 0.5*ρ*v_2^2 + ρ*g*h_2
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High velocity = low pressure
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Torricelli: exit speed = sqrt(2*g*h)
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Ideal fluid: incompressible, non-viscous, laminar
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Streamline flow
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Viscosity: internal friction between fluid layers |