Русский New site

Advanced search

[ New messages · Forum rules · Members ]
Page 64 of 64«12626364
Forum » SpaceEngine » Science and Astronomy Discussions » Science and Astronomy Questions
Science and Astronomy Questions
WatsisnameDate: Friday, 25.11.2016, 22:57 | Message # 946
Galaxy Architect
Group: Global Moderators
United States
Messages: 2604
Status: Offline
To google!

https://www.purdue.edu/newsroo....me.html





 
HuesudoDate: Monday, 28.11.2016, 21:57 | Message # 947
Observer
Group: Users
Spain
Messages: 10
Status: Offline
Without taking into account the crazy heat, would it be difficult to walk through Venus's atmosphere due to the high pressure? I have always had trouble separating pressure from density..
 
WatsisnameDate: Tuesday, 29.11.2016, 03:26 | Message # 948
Galaxy Architect
Group: Global Moderators
United States
Messages: 2604
Status: Offline
You'd feel more resistance for sure, but walking would not be very difficult. It's much denser than air at Earth's surface, but also much less dense than water.

To calculate the density of the air, it might be most convenient to start with the ideal gas law:

PV=nRT

where P is the pressure, V is the volume, n is the number of moles of gas, R is the gas constant, and T is the temperature.

Let's see if we can pull density out of that formula somehow. Density is mass per volume:

ρ=m/V

and we can say that the mass is equal to the number of moles times the molar mass:

m=nM

Therefore the density is

ρ=nM/V

Solve for n:

n=ρV/M

Now plug that in place of n in the ideal gas law:

PV=(ρV/M)*RT

Now solve for ρ:

ρ=(PVM)/(VRT) = (PM)/(RT)

So the density is equal to the air pressure times its average molar mass, divided by the gas constant, divided by the temperature.

The air at Venus' surface has a pressure of 90atm (9.12*106 Pa), an average molar mass of 0.04345kg/mol, and a temperature of 735 Kelvin. The gas constant R is 8.314 Joules per kilogram per mole. This tells us that the density of the air at Venus' surface is about 65kg/m3, which is 53 times greater than at Earth's surface, or 6.5% the density of water.

Another helpful aid for thinking about the effect of this is to consider the force of the wind (or more precisely, the dynamic pressure). The dynamic pressure is proportional to the density of the air and the square of the wind speed. So if the air on Venus is 53 times denser, then you get the same wind pressure at only 14% of the wind speed. A 7m/s wind speed on Venus would feel like a 50m/s wind speed on Earth!





 
Forum » SpaceEngine » Science and Astronomy Discussions » Science and Astronomy Questions
Page 64 of 64«12626364
Search: