89) The density of air is same at different heights.

90) The total pressure on a horizontally immersed surface is (where w = Specific weight of the liquid, A = Area of the immersed surface, and x = Depth of the centre of gravity of the immersed surface from the liquid surf

91) A body floating in a liquid is said to be in a stable equilibrium, if its metacentre coincides with its centre of gravity.

92) When an internal mouthpiece is running free, the discharge through the mouthpiece is (where a = Area of mouthpiece, and H = Height of liquid above the mouthpiece)

93) A flow through an expanding tube at increasing rate is called unsteady non-uniform flow.