Solving Gas Density Problem at Height >3000km

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SUMMARY

The discussion focuses on solving the gas density problem at altitudes exceeding 3000 km, specifically determining the height at which hydrogen and helium atom densities become equal. Given an exospheric temperature of 1500 K, initial densities of hydrogen at 500 km as 1x10^4 cm-3 and helium as 1x10^6 cm-3, the density equations are established using the formula n(z) = n0 exp(-z/H), where H is the scale height defined by H = RT/Mg(z). The participants confirm the setup involving gravitational acceleration g, which decreases with height, is appropriate for the calculations.

PREREQUISITES
  • Understanding of atmospheric density equations and scale height calculations
  • Familiarity with the ideal gas law and its application in exospheric conditions
  • Knowledge of gravitational acceleration and its variation with altitude
  • Basic proficiency in mathematical modeling and exponential functions
NEXT STEPS
  • Research the application of the ideal gas law in high-altitude atmospheric physics
  • Study the effects of temperature on gas density in the exosphere
  • Explore gravitational models and their implications on gas behavior at varying altitudes
  • Investigate numerical methods for solving exponential equations in atmospheric science
USEFUL FOR

Atmospheric scientists, aerospace engineers, and students studying high-altitude physics will benefit from this discussion, particularly those interested in gas behavior in the exosphere and related calculations.

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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
n(z) = n_{0} \exp(\frac{-z}{H})
where H is the scale height H = \frac{RT}{Mg(z)}

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

is the setup good so far? Thank you for all your help!
 
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can anyone help?

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

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