A heavy sphere attached to a string should hang at an angle O when immersed in a stream of velocity U, as in Fig.P7.80. Derive an expression for e as a function of the sphere and flow properties. What is e if the sphere is steel(SG = 7,86) of diameter 3 cm and the flow is sea-level standard air at U = 40 m/s? Neglect the string drag.

Fig: 1

Fig: 2