Practice question

**Distinction between periodic and oscillatory** clarifies all SHM is periodic but not all periodic is SHM. SHM requires linear restoring force and inertia, a ∝ -x, with ω = √(k/m). Functions like sin²ωt have period π/ω but lack a = -ω² x, thus periodic not SHM, while uniform circular motion is periodic without linear oscillation. Acceleration: a(t) = -ω² x(t) . Here, ω = 4 s⁻¹, x(0) = 3 cos ((π/3)) = 3 × 0.5 = 1.5 m . a(0) = -4² × 1.5 = -16 × 1.5 = -24 m/s² . Applying x = A cos(ωt + φ), v = -ωA sin(ωt + φ),