Golfball ‘‘dimples’’ cause the drag drop (see Figure 12.4 and the illustration for Problem 12.7) to occur at a lower Reynolds number. The table below gives the drag coefficient for a rough sphere as a...

Golfball ‘‘dimples’’ cause the drag drop (see Figure 12.4 and the illustration for Problem 12.7) to occur at a lower Reynolds number. The table below gives the drag coefficient for a rough sphere as a function of the Reynolds number. Plot the drag for1.65-in.-diameter sphere as a function of velocity. Show several comparison points for a smooth sphere.

Problem 12.7

For what wind velocities will a 12.7-mm-diameter cable be in the unsteady wake region of Figure 12.2?