For flow around a sphere the boundary layer becomes turbulent around ReD 2.5 3 105 . Find the speeds at which (a) an American golf ball (D 5 1:68 in.), (b) a British golf ball (D 5 41:1mm), and (c) a...

For flow around a sphere the boundary layer becomes

turbulent around ReD 2.5 3 105

. Find the speeds at which

(a) an American golf ball (D 5 1:68 in.), (b) a British golf

ball (D 5 41:1mm), and (c) a soccer ball (D 5 8:75 in.)

develop turbulent boundary layers. Assume standard atmospheric conditions.