This is the solution to the problem discussed at http://ankit-mathur.blogspot.com/2013/06/physics-centrifuge-problem.html
We basically need to find out the system which has more kinetic energy.
Both in system 1 and system 2, the disk rotates at the same angular velocity. Now, since the coin is also rotating in the first case, it would have additional kinetic energy. The kinetic energy of the first system is equal to the the sum of the kinetic energy of the second system and the kinetic energy of the coin rotating on its own axis. Hence, the first system has more energy.
Hence we will require more electricity to start the first system from rest.
We basically need to find out the system which has more kinetic energy.
Both in system 1 and system 2, the disk rotates at the same angular velocity. Now, since the coin is also rotating in the first case, it would have additional kinetic energy. The kinetic energy of the first system is equal to the the sum of the kinetic energy of the second system and the kinetic energy of the coin rotating on its own axis. Hence, the first system has more energy.
Hence we will require more electricity to start the first system from rest.
