Air flows past two equal sized spheres (one rough, one smooth) that are attached to the arm of a balance as is indicated in Fig. P9.87. With \(U=0\) the beam is balanced. What is the minimum air velocity for which the balance arm will rotate clockwise?

Figure P9.87

Transcribed Image Text:

D= 0.1 m Smooth sphere Rough sphere /D = 1.25 x 102 -0.3 m- 0.5 m U