Shown in Fig. 16.20 is a small decorative wheel fitted with flat paddles so the wheel turn...

Shown in Fig. 16.20 is a small decorative wheel fitted with flat paddles so the wheel turns about its axis when acted on by a blown stream of air. Assuming that all the air in a 15-mm-diameter stream moving at 0.35 m/s strikes one paddle and is deflected by it at right angles, compute the force exerted on the wheel initially when it is stationary. The air has a density of 1.20 kg/m3.

FIGURE 16.20