Many Men wrote:
The altitudes cited here are much, much higher than 5,000 feet. Do you think there is as big of a difference at a lower altitude?
There is only a difference of 6% altitude for equal atmospheres between the summit of Mt. McKinley and the corresponding Himalayan height. I imagine at a lower altitude, this difference would be even smaller. Probably negligible.
The the differences in gravity are so minute that there would be no noticeable differences in gas concentrations caused by the differences in gravity.
Boulder 40’ Lattitude g
b
= ???? m/s
2
New York 40’ Lattitude g
ny
= 9.802m/s
2
g
ny
/g
b
= (r
b
/ r
ny
)
2
9.802/g
b
= (6369.6km/6368km)
2
9.802/g
b
= 1.00025126
2
9.802/1.0005 = g
b
= 9.797m/s
2
The pull of gravity at Boulder is 99.94899% compared to New York City. Translation: negligible
--------------------------
The Earths radius at the equator is 6378km. The differences in gravity at 5000’ at 40 latitude compared to 5000’ 0 latitude is:
g
e
/g
b
= (r
b
/ r
e
)
2
g
e
/9.797 = (6369.6km/6379.6km)
2
g
e
= (0.9968674)*(9.797) = 9.766 m/s
2
The pull of gravity at 5000' on the equator is 99.968% of Boulder's gravity. Translation: negligible
------------------
The reason why running is easier at altitude at the equator than at mid latitudes is due to change in the pressure gradients, as already posted by a previous rocket scientist.