An insulated tank contains 50 kg of water at 30oC, which is stirred by a paddle wheel

Question:

An insulated tank contains 50 kg of water at 30oC, which is stirred by a paddle wheel at 300 rpm while transmitting a torque of 0.2 kNm. Determine
(a) The rate of change of temperature (dT/dt)
(b) The rate of change of total entropy (dS/dt).
(c) The rate of generation of entropy (Sgen) within the tank. Assume s = 4.2lnT and u = 4.2T, where T is in Kelvin.