Physics

Force

Push/pull that can change an object's motion (vector quantity)

Net Force

Sum of all forces acting on an object (F_net = ma)

Inertia

Tendency of objects to resist motion changes (Newton's 1st Law)

Friction

Force opposing motion (static > kinetic)

Normal Force

Perpendicular surface contact force

Free Body Diagram

Visual representation of all forces acting on an object

1st Law (Inertia)

Object maintains velocity unless net force acts

2nd Law (F=ma)

Acceleration ∝ net force, ∝ 1/mass

3rd Law

For every action, equal/opposite reaction

Terminal Velocity

Max speed when drag = weight

Centripetal Force

F = mv²/r (always points toward center)

Work

W = Fdcosθ (energy transferred)

Kinetic Energy

KE = ½mv²

Potential Energy

PE = mgh (gravitational)

Conservation of Energy

Total energy constant in closed system

Momentum

p = mv (conserved in collisions)

Impulse

J = FΔt = Δp

1st Law of Thermodynamics

ΔU = Q - W (energy conservation)

2nd Law of Thermodynamics

Entropy always increases in spontaneous processes

Conduction

Heat transfer through solids (metal rod heating)

Convection

Heat transfer through fluids (boiling water)

Radiation

Heat transfer via EM waves (sunlight)

Specific Heat

Energy to raise 1g by 1°C (water = 4.18 J/g°C)

Transverse Wave

Oscillations perpendicular to direction (light)

Longitudinal Wave

Oscillations parallel to direction (sound)

Wave Equation

v = fλ (speed = frequency × wavelength)

Doppler Effect

Frequency change due to motion (↑ pitch approaching)

P-Waves

Fastest seismic waves, travel through solids and liquids

S-Waves

Slower seismic waves, travel through solids only

Pressure

P = F/A (Pa = N/m²)

Buoyancy

F_b = ρVg (Archimedes' Principle)

Bernoulli's Equation

P + ½ρv² + ρgh = constant

Continuity Equation

A₁v₁ = A₂v₂ (flow rate conserved)

Viscosity

Resistance to flow (honey > water)

Coulomb's Law

F = kq₁q₂/r² (electrostatic force)

Ohm's Law

V = IR (voltage = current × resistance)

Series Circuit

Current same, voltage splits

Parallel Circuit

Voltage same, current splits

Right-Hand Rule

Thumb = current, fingers = magnetic field

Reflection

θ_incident = θ_reflected

Refraction

n₁sinθ₁ = n₂sinθ₂ (Snell's Law)

Lens Equation

1/f = 1/d₀ + 1/dᵢ

Converging Lens

Forms real/inverted or virtual/upright images

Diffraction

Wave bending around obstacles (λ↑ → bending↑)

Photoelectric Effect

Light as particles (E = hf)

Relativity

Time dilation: Δt' = Δt/√(1-v²/c²)

Quantum Theory

Energy is quantized (E = nhf)

Alpha Decay

Releases ⁴He²⁺ (2 protons, 2 neutrons)

Beta Decay

Releases high-speed electron (β⁻)

Gamma Decay

Releases high-energy photon (γ, no mass/charge)