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Hazarrd
Apr13-04, 10:26 PM
Im doing research on skydiving and I am trying to find out how much drag is created on different jumps. I have different velocities for each of the jumps.

D = Cd ((rV^2)/2)A

That is the equation I am using. r is air density which im using 1.2 kg/m^3. V is the velocity. And ive measured the skydivers approximate area (A) to be .871 square meters. How do I find Cd (Drag coefficient)? Is this a constant? Is there somewhere I can get some more information on what Cd would be? Thanks!

FUNKER
Apr14-04, 01:54 AM
you have to calculate the coeffiecent on a basis where that is the unknown and then just re arrange, and to my belief the drag co-efficient is a constant that varies with the fluid the object is travelling in be it air water or honey.

Stingray
Apr14-04, 10:35 AM
Cd depends mostly on the shape of the object, and very weakly on something called Reynold's number. There's no simple way to calculate Cd, so its usually just measured experimentally. Here are some examples with simple shapes: http://www.insideracingtechnology.com/tech102drag.htm.