Flow past a long cylinder of square cross-section results in more drag than the comparable round cylinder. Here are data taken in a water tunnel for a square cylinder of side length b = 2 cm:
V, m/s:
1.0 2.0 3.0 4.0
Drag, N/(m of depth): 21 85 191 335
(a) Use this data to predict the drag force per unit depth of wind blowing at 6 m/s, in air at 20°C, over a tall square chimney of side length b = 55 cm.
(b) Is there any uncertainty in your estimate?