The 75 -kg flywheel has a radius of gyration about its shaft axis of $\bar{k}=0.50 \mathrm{m}$ and is subjected to the torque $M=10\left(1-e^{-t}\right) \mathrm{N} \cdot \mathrm{m},$ where $t$ is in seconds. If the flywheel is at rest at time $t=0$ determine its angular velocity $\omega$ at $t=3$ s.