(a) Identify the controlled, manipulated and disturbance variables in the following level control system. ( 5 marks) (b) The above drawing depicts a feedback control system. Show, through a drawing, how you would implement a feedforward control approach. ( 5 marks) (c) What is the main difference between feedback and feedforward control strategies? (5 marks) (d) If the flow in is Qi, the flow out is Q0, the level height in the tank is H and Q0= HIR where R is the control valve flow resistance derive a dynamic relationship between the tank level H(t) and the flow in Q(t). Assume a fluid constant density . (5 marks) (e) Find the process transfer function expressing the level output H(s) over the flow rate input Q (s)