⚛️ NEB & CEE Physics: 50 Most Important MCQs from Mechanics
Laws of Motion | Friction | Work Energy Power | Circular Motion | Rotational Motion | 24 May 2082
📚 Mechanics: Complete Formula Recap for NEB & CEE (24 May)
🔹 Newton's Laws of Motion: First Law (Inertia), Second Law (F = ma), Third Law (Action-Reaction). Impulse = Change in momentum = F·Δt. Conservation of linear momentum: m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂.
🔹 Friction: Static friction (fₛ ≤ μₛN), Kinetic friction (fₖ = μₖN). Angle of repose: tanθ = μₛ. Angle of friction: tanα = μ. Rolling friction is less than sliding friction.
🔹 Work, Energy & Power: Work = F·s·cosθ. Kinetic Energy = ½mv². Work-Energy Theorem: W = ΔKE. Potential Energy = mgh. Conservation of Mechanical Energy: KE + PE = constant. Power = Work/Time = F·v.
🔹 Circular Motion: Centripetal acceleration a_c = v²/r = ω²r. Centripetal force F_c = mv²/r = mω²r. Banking of roads: tanθ = v²/rg. Conical pendulum: T = 2π√(l cosθ/g). Motion in vertical circle: Tension at lowest point = mv²/r + mg, at highest = mv²/r - mg.
🔹 Rotational Motion: Moment of inertia (I) = Σmr². For rod (center): I = ML²/12; (end): I = ML²/3. Torque τ = Iα. Angular momentum L = Iω. Conservation of angular momentum: I₁ω₁ = I₂ω₂. Rotational KE = ½Iω². Rolling motion: KE_total = ½mv² + ½Iω².
💡 Exam Tips: In CEE, 12-14 questions come from Mechanics. Focus on numericals from Newton's laws, work-energy theorem, centripetal force, and moment of inertia. Practice free body diagrams for friction and pulley problems.