$3\mathrm{.}2.$b A $100$MVA,$13\mathrm{.}8kV,50Hz4-$pole generator has an inertia constant of $10M\frac{J}{M}VA.$ a$)$ find the stored energy in the rotor at Synchronous speed b$)$ if the input to the generator suddenly raised to $60$ MW for an electrical load of $50$ MW $,$ find rotor acceleration, c$)$ if the rotor acceleration calculated in part b$)$ is maintained for $10$ cycle find the torque angle and rotor speed in rpm at the end of the period.