Practice question

Given: A spring system has m = 0.1 kg, k = 40 N/m, A = 10 cm . What is the kinetic energy at x = 5 cm ? These values define the system as per NCERT data. Formula: Total energy: E = 1/2 k A² = 0.5 × 40 × (0.1)² = 0.2 J. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Potential energy: U = 1/2 k x² = 0.5 × 40 × (0.05)² = 0.05 J . Kinetic energy: K = E - U = 0.2 - 0.05 = 0.15 J . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.