Hacker Newsnew | past | comments | ask | show | jobs | submitlogin

The frontal area of two spheres of the same mass will be determined by the sphere's density, and that drives the air resistance.

If frontal area didn't matter to drag, wouldn't all spheres would have the same drag coefficient?

From that page:

Cd = D/(rAV^2/2) where A is frontal area.

What am I missing?



> Cd = D/(rAV^2/2) where A is frontal area.

You're citing a page that uses the word "density" differently than you do.

"D" is density-of-the-air. The density you're talking about appears to be the density-of-the-sphere.


It absolutely is, and will then drive differences in reference area, thus affecting the drag of the object.


"Appears to be"?

They explicitly said so.

Twice.


You’re missing nothing, you’re correct.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: