KINEMATICS:
  Equations of motion (uniform acceleration):
    v = u + at
    s = ut + ½at²
    v² = u² + 2as
  
  Free fall: a = g = 9.8 m/s² downward
  Projectile: horizontal (constant velocity) + vertical (gravity)
    Time of flight: T = 2u sinθ/g
    Maximum height: H = u²sin²θ/2g
    Horizontal range: R = u²sin2θ/g

NEWTON'S LAWS:
  1st Law: body at rest stays at rest, body in motion stays in motion unless acted upon
  2nd Law: F = ma (net force causes acceleration)
  3rd Law: every action has equal and opposite reaction on DIFFERENT bodies
  
  Free body diagram approach:
    Isolate the object
    Draw all forces: weight (mg down), normal (N up or perpendicular)
    Tension T in string, friction f opposing motion
    Apply F_net = ma in each direction

WORK AND ENERGY:
  Work: W = F·d·cosθ (θ = angle between force and displacement)
    Positive work: force and displacement in same direction
    Negative work: force opposes displacement (friction)
    Zero work: force perpendicular to displacement (normal force)
  
  Kinetic Energy: KE = ½mv²
  Potential Energy (gravitational): PE = mgh
  Conservation: if no non-conservative forces: KE₁ + PE₁ = KE₂ + PE₂

CIRCULAR MOTION:
  Centripetal acceleration: a = v²/r = ω²r (directed toward centre)
  Centripetal force: F = mv²/r (net force toward centre — NOT extra force)
  Banking angle: tan θ = v²/rg (for frictionless banked road)

COULOMB'S LAW: F = kq₁q₂/r² (k = 9×10⁹ N.m²/C²)
  Vector form: force along line joining charges
  Attractive for unlike charges | repulsive for like charges

ELECTRIC FIELD: E = F/q₀ = kQ/r²
  Field lines: start from positive, end at negative
  Never cross | closer = stronger field
  Inside conductor: E = 0 (charges redistribute)

POTENTIAL: V = kQ/r (scalar, not vector)
  Work done = q(V₁ - V₂) (positive charge moves from high V to low V)
  E = -dV/dr (negative gradient of potential)

CAPACITOR: stores charge and energy
  Q = CV | Energy = ½CV² = Q²/2C
  Parallel plate: C = ε₀A/d | with dielectric: C = Kε₀A/d
  Combination: Series: 1/C = Σ1/Cᵢ | Parallel: C = ΣCᵢ