Some curious experiments (TEFC)

Description: Episode number 1 of Series “Fluid Dynamics of Drag”. Professor Ascher M. Shapiro describes experiments to show that in a certain range of speeds the drag of a sphere decreases as the speed increases; that at low speed a smooth sphere has less drag than a rough sphere, while at high speeds it is just the reverse; that stream lining reduces drag in air, but increases drag in glycerine.