Its the human feel of moisture... that's heavy
First consider the atmospheric pressure at elevationsSite Atm. Pressure:
El, ft psia El, m mm Hg mbar
-200 14.80 -61 765 1021
0 14.70 0 760 1013
200 14.59 61 755 1006
700 14.33 213 741 988
1200 14.07 366 728 970
1700 13.82 518 715 953
2200 13.57 671 702 935
2700 13.32 823 689 918
3200 13.08 976 676 902
3700 12.84 1128 664 885
4200 12.60 1280 652 869
4700 12.37 1433 640 853
5200 12.14 1585 628 837
5700 11.92 1738 616 822
6200 11.70 1890 605 806
6700 11.48 2043 594 791
7200 11.27 2195 583 777
7700 11.06 2348 572 762
8200 10.85 2500 561 748
8700 10.65 2652 551 734
Applying a little pv=nrt and vapor pressure of water, one can see that warm air can carry a lot of moisture and how much density of air is affected by elevation, , what a drag... at sea level.. or below
Sea Level, Dry Air
temp, F 40 60 80 100
temp, C 4.4 15.6 26.7 37.8
pres, mmHG 760 760 760 760
% RH. 0 0 0 0
% Vol. Mois 0.00% 0.00% 0.00% 0.00%
mw 28.979 28.979 28.979 28.979
acf/lbmol 364.807 379.411 394.015 408.619
lb/ft3 0.079 0.076 0.074 0.071
Sea Level, 50% Relative Humidity
temp, F 40 60 80 100
temp, C 4.4 15.6 26.7 37.8
pres, mmHG 760 760 760 760
% RH 50 50 50 50
% Vol. Moist 0.41% 0.86% 1.71% 3.21%
mw 28.861 28.729 28.483 28.050
acf/lbmol 364.807 379.411 394.015 408.619
lb/ft3 0.079 0.076 0.072 0.069
Sea Level, 85% Relative Humidity
temp, F 40 60 80 100
temp, C 4.4 15.6 26.7 37.8
pres, mmHG 760 760 760 760
% RH 85 85 85 85
% Vol. Moist 0.70% 1.47% 2.91% 5.45%
mw 28.778 28.554 28.136 27.399
acf/lbmol 364.807 379.411 394.015 408.619
lb/ft3 0.079 0.075 0.071 0.067
4700 Ft elevation, 0% relative Humidity
temp, F 40 60 80 100
temp, C 4.4 15.6 26.7 37.8
pres, mmHG 640 640 640 640
% RH 0 0 0 0
% Vol. Moist 0.00% 0.00% 0.00% 0.00%
mw 28.979 28.979 28.979 28.979
acf/lbmol 433.209 450.551 467.893 485.235
lb/ft3 0.067 0.064 0.062 0.060
4700 Ft elevation, 50% relative Humidity
temp, F 40 60 80 100
temp, C 4.4 15.6 26.7 37.8
pres, mmHG 640 640 640 640
% RH 50 50 50 50
% Vol. Moist 0.49% 1.03% 2.03% 3.81%
mw 28.839 28.682 28.390 27.875
acf/lbmol 433.209 450.551 467.893 485.235
lb/ft3 0.067 0.064 0.061 0.057
4700 Ft elevation, 85% relative Humidity
temp, F 40 60 80 100
temp, C 4.4 15.6 26.7 37.8
pres, mmHG 640 640 640 640
% RH 85 85 85 85
% Vol. Moist 0.83% 1.74% 3.46% 6.48%
mw 28.740 28.474 27.978 27.103
acf/lbmol 433.209 450.551 467.893 485.235
lb/ft3 0.066 0.063 0.060 0.056
Looking at equation for drag forces on a body below.. given the coefficient of drag, velocity, and frontal area of ball are constant, drag is proportional to density of fluid (air).. drag goes down, ball should go farther, though lift is also reduced as temps go up and elevation goes up...
from
http://www.engineeringtoolbox.com/drag-coefficient-d_627.htmlDrag force can be expressed as:
Fd = cd 1/2 ρ v2 A (1)
where
Fd = drag force (N)
cd = drag coefficient
ρ = density of fluid
v = flow velocity
A = characteristic frontal area of the body
The drag coefficient is a function of several parameters like shape of the body, Reynolds Number for the flow, Froude number, Mach Number and Roughness of the Surface. (These are normally determined experimentally)