A circular solid disc of uniform thickness $20 \mathrm{~mm},$ radius $200 \mathrm{~mm}$ and mass $20 \mathrm{~kg}$, is used as a flywheel. If it rotates at $600 \mathrm{rpm},$ the kinetic energy of the flywheel, in Joules is
(A) 395
(B) 790
(C) 1580
(D) 3160
A circular solid disc of uniform thickness $20 \mathrm{~mm},$ radius $200 \mathrm{~mm}$ and mass $20 \mathrm{~kg}$, is used as a flywheel. If it rotates at $600 \mathrm{rpm},$ the kinetic energy of the flywheel, in Joules is
(A) 395
(B) 790
(C) 1580
(D) 3160