[freebeard]

2) Then you need to find something like a high-school, or junior-college laboratory, which has a scientific-quality electronic, load-cell type scale, with an accuracy in fractions of a gram, and weigh your cardboard rectangle.

Else one gram accuracy and use 10 cut-outs.

( anyone with 'Aerodynamik des Kraftfahrzeugs' will see the genesis of this relationship through the researches of Walter Lay, Baron Reinhard-von Fachsenfeld, and Dr. Wunibald I. Kamm ).

I thought there was a guy named W. A. Mair

www.cambridge.org: Reduction of Base Drag by Boat-Tailed Afterbodies in Low-Speed Flow