A carnival merry-go-round has a large disk-shaped platform of mass 120 kg that can rotate about a center axle. a 60 kg student stands at rest at the edge of the platform 4.0 m from its center. The platform is also at rest. The student starts running clockwise around the edge of the platform and attains a speed of 2.0 m/s relative to the ground.
a) Decide the rotational velocity of the platform.
b) Decide the change of kinetic energy of the system consisting of the platform and the student.
c) Draw bar charts for these