A body oscillates with SHM according to \( x = 4 \cos (2\pi t + \frac{\pi}{6}) \) (in SI units). What is its velocity at
**Resonance phenomenon** amplifies response when driving frequency matches natural frequency ω_d ≈ ω₀, large amplitude even with small F₀, as damping limits growth. Natural frequency determined by system parameters, resonance condition crucial for understanding vibrations and energy absorption, e.g., bridge collapse, tuning. Velocity: v(t) = -ω A sin (ω t + Φ) . Here, A = 4 m, ω = 2π s⁻¹, Φ = (π/6) . At t = 0.5 s : ω t + Φ = 2π × 0.5 + (π/6) = π + (π/6) = (7π/6) . sin (7π/6) = sin (180° + 30°) = -sin 30° = -(1/2) . v = -2π
Ref: NCERT > Physics Book > Oscillations > Forced Oscillations and Resonance