trail wrote:
devashish_paul wrote:
The
atmospheric pressure is also your big drag countributor. Humidity is the last thing on this list.
I think it's more accurate so say that air density can affect aerodynamic drag significantly. Air density is a function of atmospheric pressure, temperature, and humidity. All three can have significant effects on air density.
For any volume of gas, there are an equal number of molecules (Avogadro's). When air is humid, water vapor (a gas) displaces dry air molecules. Because (counter-intuitively) water vapor has less molar mass than dry air, the density of that volume of gas decreases the more water vapor there is in it.
All true. But, most of us run/bike more slowly on hot, humid days when we're going any sort of distance. It must help if you're running a 100m sprint to have hot, humid days, but it doesn't help my 10k run or 40k bike times.
(Somewhat) interesting connection. Atlanta-Fulton County Stadium was known as "The Launching Pad" when the Atlanta Braves played there. The high temperatures, high humidity, and (relatively) high field elevation (1050 feet above sea level) generally made the air less dense there than at other MLB fields. Once you hit a ball, having less dense air will allow it to travel further for a given initial velocity. Hank Aaron would have hit a bunch of home runs anywhere, but the fact that he played there (from 1966) probably helped him.
"Human existence is based upon two pillars: Compassion and knowledge. Compassion without knowledge is ineffective; Knowledge without compassion is inhuman." Victor Weisskopf.