Page:Aerial Flight - Volume 1 - Aerodynamics - Frederick Lanchester - 1906.djvu/407

Rh {| align="center" style="text-align: center; width: 100%"
 * align="right" width="1%" | || width="1%" | $$13^2\ n + \frac{(.875 - 17^2 n) \times 17^2}{13^2} = 1.26$$ || width="1%" |
 * align="right" | || $$169\ n - 494\ n = 1.26 - 1.495$$ ||
 * align="left" | or, || $$325\ n = .235$$ ||
 * || $$n = .000724$$ ||
 * align="left" | or, || $$x = .000724\ V^2\ \mbox{grams.}$$ ||
 * align="left" colspan="3" | or, in poundals per square foot
 * }
 * || $$n = .000724$$ ||
 * align="left" | or, || $$x = .000724\ V^2\ \mbox{grams.}$$ ||
 * align="left" colspan="3" | or, in poundals per square foot
 * }
 * align="left" colspan="3" | or, in poundals per square foot
 * }

the deduction .0015 being made, as in the last example, for ballast resistance.

Determination of constant $$c .$$

all quantities in absolute units.

Thus, for the determination of $$c$$ in any particular case the value of $$m$$ must first be obtained from the equations, the remaining quantities in the expression $$A$$ and $$W$$ being the area (sq. ft.) and weight (poundals) of the aeroplanes employed.

Example.—Planes 1 and 2.

Flight data as given.

A.F.