Solving Gas Density Problem at Height >3000km

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In summary, the conversation is about determining the height at which the densities of hydrogen and helium atoms become equal in the atmosphere. The given information includes the exospheric temperature, hydrogen and helium atom densities at 500 km, and the acceleration due to gravity, which decreases with height. The setup for calculating the equal densities is also discussed.
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stunner5000pt
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If the exospheric temperature is 1500 K and the hydrogen atom and helium atom densities at 500 km are 1x10^4 cm-3 and 1x10^6 cm-3 respectively, determine at what height the hydrogen atom and helium atom densities will become equal. [Hint: The answer is greater than 3000 km and remember that the acceleration due to gravity g decreases with height]

wel the densities of the gases in the atmosphere is given by
[tex] n(z) = n_{0} \exp(\frac{-z}{H}) [/tex]
where H is the scale height [tex] H = \frac{RT}{Mg(z)}[/tex]

the densities of H are 10^10 m-1 and He 10^12 m-1
when the densities are equal
[tex] 10^{10} \exp\left(\frac{-zg(z)}{1.2 * 10^7}\right) = 10^{12} \exp\left(\frac{-zg(z)}{3.1*10^6}\right) [/tex]
where [tex] g = \frac{GM}{z^2} [/tex]

is the setup good so far? Thank you for all your help!
 
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  • #2
bump !

can anyone help?

i just want to know if the setup is correct or not!
 

1. What is gas density and why is it important when solving problems at heights over 3000km?

Gas density refers to the amount of mass per unit volume of a gas. It is an important factor to consider when solving problems at high altitudes because it affects the behavior and properties of gases, such as pressure and temperature. At higher altitudes, the gas density decreases, which can impact the performance of aircraft and spacecraft, as well as the conditions for human survival.

2. How do you calculate gas density at heights over 3000km?

Gas density at high altitudes can be calculated using the ideal gas law, which states that the density of a gas is directly proportional to its pressure and inversely proportional to its temperature. The equation is: density = (pressure * molecular weight) / (gas constant * temperature).

3. What are some challenges in solving gas density problems at heights over 3000km?

One of the main challenges in solving gas density problems at high altitudes is the variation in air pressure and temperature. These factors can change rapidly and are affected by factors such as altitude, weather, and location. Additionally, the ideal gas law may not always accurately predict gas behavior at extreme heights and conditions.

4. How do you account for changes in gas density when designing aircraft or spacecraft for high altitude operations?

When designing for high altitude operations, engineers and scientists must consider the changing gas density and its impact on the performance of the vehicle. This can be done through careful calculations and simulations, as well as using specialized materials and technologies to withstand the extreme conditions.

5. What are some real-world applications of solving gas density problems at heights over 3000km?

Solving gas density problems at high altitudes has many practical applications, such as in the design and operation of aircraft, spacecraft, and weather balloons. It is also important in understanding the atmospheric conditions on other planets and in predicting the behavior of gases in various industrial processes. Additionally, it is crucial in ensuring the safety and survival of astronauts and high-altitude pilots.

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