FIGURE 15-20
-A paint sprayer pumps air through a constriction in a 2.50-cm diameter pipe, as shown in Figure 15-20. The flow causes the pressure in the constricted area to drop and paint rises up the feed tube and enters the air stream. The air stream in the 2.50-cm diameter sections is 5.00 m/s. The density of the air is 1.29 kg/m³, and the density of the paint is 1200 kg/m³. What is the maximum diameter of the constriction that will allow the sprayer to operate?

Question

FIGURE 15-20

-A paint sprayer pumps air through a constriction in a 2.50-cm diameter pipe, as shown in Figure 15-20. The flow causes the pressure in the constricted area to drop and paint rises up the feed tube and enters the air stream. The air stream in the 2.50-cm diameter sections is 5.00 m/s. The density of the air is 1.29 kg/m³, and the density of the paint is 1200 kg/m³. What is the maximum diameter of the constriction that will allow the sprayer to operate?

Quizplus · Accepted Answer

Using Bernoulli's equation and the continuity equation, the maximum diameter of the constriction can be calculated to ensure the pressure drop is sufficient to lift the paint. The correct calculation leads to a diameter of 8.09 mm.

FIGURE 15-20 -A Paint Sprayer Pumps Air Through a Constriction in a Constriction