2. A motor is rated to be 200 kW and rotates at 1000 rpm. The diameter and axial length of the core of an armature are 50.0 cm and 25.0 cm, respectively. The total J value of the armature's winding and other moving parts is the same as that of the core. The density of the core's material is 8000 kg/m^3. The motor is rotating at 1000 rpm at its rated power, 200 kW. Calculate the rotational kinetic energy of the core. Calculate the rotational kinetic energy of the core and all revolving parts when the motor rotates at 500 rpm at 200 kW.

2. A motor is rated to be 200 kW and rotates at 1000 rpm. The diameter and axial length of the core of an armature are 50.0 cm and 25.0 cm, respectively. The total J value of the armature's winding and other moving parts is the same as that of the core. The density of the core's material is 8000 kg/m^3. The motor is rotating at 1000 rpm at its rated power, 200 kW. Calculate the rotational kinetic energy of the core. Calculate the rotational kinetic energy of the core and all revolving parts when the motor rotates at 500 rpm at 200 kW.