Page:Aerial Flight - Volume 1 - Aerodynamics - Frederick Lanchester - 1906.djvu/405

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EXPERIMENTAL AERODYNAMICS.
§ 245
Or,  
[1]
(1)
(2)
Now we know that and where and are constants,
or, (3)
(4)
By (1) and (3) (5)
By (2) and (4) (6)
or,
or,


multiplying by to obtain grams per square foot, and by to convert to British absolute units, we have—

But normal plane pressure is given by expression—


or,

In the foregoing calculation no allowance has been made for

  1. In these experiments the hypothesis of the small angle is taken as applying to values; is expressed in radians.

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