Topic: Engineering Mechanics
The pulley system has a mass of 1.5 kg and radius of gyration of 0.2 m. The angular acceleration of the pulleys, when the suspended masses are released is
- A. 5 rad/sec²
- B. 10/1.3 rad/sec²
- C. 15/1.3 rad/sec²
- D. 10 rad/sec²
Answer: B. 10/1.3 rad/sec²
Explanation: The total moment of inertia I_total = I₁ + I₂ + I₃ = 0.06 + 0.04 + 0.03 = 0.13 kg-m². The net torque τ = m₃gr₃ - m₂gr₂ = 3*10*0.1 - 1*10*0.2 = 3 - 2 = 1 N-m. Angular acceleration α = τ / I_total = 1 / 0.13 = 100/13 ≈ 10/1.3 rad/sec².