A solid cylinder of mass $20 \mathrm{~kg}$ rotates about its axis with angular speed $100 \mathrm{rad} / \mathrm{s}$. The radius of the cylinder is $0.25 \mathrm{~m}$. What is the kinetic energy associated with the rotation of the cylinder? What is the magnitude of angular momentum of the cylinder about its axis?
(a) $3125 \mathrm{~J}, 62.5 \mathrm{~J}-\mathrm{s}$
(b) $72.5 \mathrm{~J} \mathrm{~s}$ and $62.5 \mathrm{~J}-\mathrm{s}$
(c) $3125 \mathrm{~J}, 82.5 \mathrm{~J}-\mathrm{s}$
(d) None of the above