Question Detail

Initial angular speed ω₀ = 500 rpm = 500 × (2π/60) = (1000π/60) = (100π/6) ≈ 52.36 rad/s. Time t = 20 min = 1200 s. Angular acceleration α = (ω - ω₀)/t = (0 - 52.36)/1200 ≈ -0.04363 rad/s². Torque τ = Iα. The problem doesn't provide I, but if we assume it's a standard disk I = (1/2)MR², we'd need M and R. Alternatively, if the answer is -43.6 Nm, it implies I was about 1000 kg m². Without I, we can't calculate, but the provided options suggest -43.6 Nm is the intended correct answer based on some assumed I.