Clift et al. [46] give the formula F (6 /5) (4 + a/b) Ub for the drag

Clift et al. [46] give the formula F ≈ (6π /5) (4 + a/b) μUb for the drag of a prolate spheroid in creeping motion, as shown in Fig. P7.52. The half-thickness b is 4 mm. See also [49]. If the fluid is SAE 50W oil at 20°C, (a) check that Reb < 1; and (b) estimate the spheroid length if the drag is 0.02 N