Practice question

Given: A 1200 kg car turns on a banked road ( θ = 25°, μ_s = 0.25 ) with radius 60 m . What is the optimum speed to avoid friction? (Take g = 10 m/s², tan 25° approx 0.466 ) These values define the system as per NCERT data. Formula: Optimum speed occurs when banking alone provides ntripetal force: v_0 = sqrtrg tanθ. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Substitute: r = 60 m, g = 10 m/s², tan 25° = 0.466 . v_0² = 60 × 10 × 0.466 = 600 × 0.466 = 279.6 . v_0 = sqrt279.6 approx 16.72 m/s . 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.