Air at 20°C is drawn into the hose of a vacuum cleaner through a head that is relatively free of obstructions (the flow can be assumed to be inviscid). Estimate the velocity in the hose if the vacuum in the hose measures:
(a) 2 cm of water
(b) 8 cm of water
(c) 1 in. of water
(d) 4 in. of water