(a) Explain with the aid of a simple sketch Ullage and Sounding of a tank. (6)

(b) A deep tank 10 m wide and 10 m deep has a rectangular manhole of 1.2 m X 0.6 m at the forward end. The longer sides of the manhole are horizontal and its lower edge is 0.7 m from the bottom of the tank. Find the thrust experienced by the manhole cover when the tank has oil of RD 0.8 to an ullage of 1 m (10)