Bernoulli ;s principle applies to Venturi tubes that are used in many practical devices such as "air brush" painters, vacuum systems, carburetors, water bed drains and many other devices. One such system used to spray fertilizer is shown in Fig. 6.42. Port A is connected to a water supply that is directed through the venturi. At the throat of the Venturi, Port B is connected to the supply of fertilizer concentrate from a container below. Port C is the spray nozzle that directs the diluted fertilizer solution out to the plants. Port A, 10 mm in diameter, is connected to a water supply that reads 180 kPa while flowing at 12 L/min. Determine the vacuum pressure in the 3.5-mm-diameter throat if the metering valve is completely closed. Explain what will happen to the fertilizer concentrate in the container below as the metering valve is opened.
