Practice question
Question
A wheel with moment of inertia 6kg m2 rotates at 3rad/s. A torque of 12Nm acts for 3s. What is its final angular velocity?
Explanation
α = τI = 126 = 2rad/s2. Δω = αt = 2×3 = 6rad/s. ω = ω0+Δω = 3+6 = 9rad/s. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 9 rad/s. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.