260) The pressure of air __________ with the increase of height from the surface of the earth.

261) The sheet of water flowing over a notch or a weir is known as

262) A body floating in a liquid is said to be not in equilibrium if its metacentre lies below its centre of gravity.

263) A flow in which the quantity of liquid flowing per second is not constant, is called

264) In a sharp-crested weir, the thickness of the weir is kept less than half of the height of water above the crest of the weir.