A track is mounted on a large wheel that is free to turn with negligible friction about a vertical axis. A toy train of mass m = 0.150 kg is placed on the track and, with the system initially at rest, the train's electrical power is turned on. The train reaches a steady speed 0.14 m/s with respect to the track. What is the angular speed of the wheel if its mass is 1.4m and its radius is 0.40 m? (Treat the wheel as a hoop, and neglect the mass of the spokes and hub.) Answer in (rad/s).