Given, Power ($P$) = $100\text{ kW} = 100 \times 10^3\text{ W}$ Angular speed ($\omega$) = $1800\text{ rev/min}$ First, convert angular speed from rev/min to rad/s: $\omega = 1800 \times \frac{2\pi}{60}\text{ rad/s} = 60\pi\text{ rad/s}$ We know the relation between power, torque ($\tau$), and angular speed is: $P = \tau\omega$ $\Rightarrow \tau = \frac{P}{\omega}$ $\tau = \frac{100 \times 10^3}{60\pi} = \frac{10000}{6\pi} = \frac{5000}{3\pi}$ $\tau \approx \frac{5000}{3 \times 3.14} \approx \frac{5000}{9.42} \approx 530.7\text{ N m} \approx 531\text{ N m}$