need help with part b, c, and d

Shown below is a continuously-fed, heated, stirred tank. The goal is to maintain the outlet stream temperature at a desired value, Td " "F" represents volumetric flow. a) List some of the possible disturbances that might cause the outlet T to deviate from Td. b) Sketch the predicted outlet temperature transient that would result from a step increase in the inlet temperature during open-loop operation. c) Describe/sketch a single feedback control loop whose goal is to maintain constant outlet temperature regardless of the disturbance. d) Derive the unsteady state material and energy balances that describe this process. Simplify the model for the case of constant flows, in and out