- #1
courtney1121
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While you were under the impression that you would be working at the international space station on a project involving biomechanics in a weightless environment, your boss has other ideas. Apparently, Spacetronics has developed a new material to be used for a heat shield on the newest version of the space shuttle. They are very proud of this material and hope to convince NASA to use it (there’s lots of money to be made)! Since it is way too expensive to test out the material, your boss has asked you to determine whether the material will work for the heat shield. She did note that your next project would be at the space station and involving biomechanics. She also pointed out that you would be taking the newly outfitted space shuttle home. So it is important that you get this right, or you would be toast, literally.
The space shuttle is cylindrical with a diameter of 8.7 meters and a length of 56.14 m. The mass of the shuttle is two million kilograms. The shuttle would be coated with the material, 2 cm thick. The new material has a specific heat of 1000 J/kg K, and a density of 2500 kg/m3. If the temperature of the material exceeds 4000K, it will spontaneously combust, resulting in the shuttle exploding. You already know that as the shuttle enters the atmosphere at 100 km, it will experience a drag force, so while some of the potential energy will be converted to kinetic energy, some will also be converted to thermal energy. Hence, you need to be able to determine the speed of the shuttle as it falls to the earth, so that you can determine how much heat the shield will absorb, hence its temperature. The density of the atmosphere is given by the following expression:
p= p0exp* -(MWgz/RT)
where r0 is the density of air at the surface of the earth, MW is the average molecular weight of air in kilograms per mole (not grams per mole), T is the temperature in Kelvin and R = 8.314 J/mol K.
Well I know:
m= 2 million kg
specific heat = 1000J/kg K
density = 2500kg/m3
Tempmax = 4000K
where should I get started?
The space shuttle is cylindrical with a diameter of 8.7 meters and a length of 56.14 m. The mass of the shuttle is two million kilograms. The shuttle would be coated with the material, 2 cm thick. The new material has a specific heat of 1000 J/kg K, and a density of 2500 kg/m3. If the temperature of the material exceeds 4000K, it will spontaneously combust, resulting in the shuttle exploding. You already know that as the shuttle enters the atmosphere at 100 km, it will experience a drag force, so while some of the potential energy will be converted to kinetic energy, some will also be converted to thermal energy. Hence, you need to be able to determine the speed of the shuttle as it falls to the earth, so that you can determine how much heat the shield will absorb, hence its temperature. The density of the atmosphere is given by the following expression:
p= p0exp* -(MWgz/RT)
where r0 is the density of air at the surface of the earth, MW is the average molecular weight of air in kilograms per mole (not grams per mole), T is the temperature in Kelvin and R = 8.314 J/mol K.
Well I know:
m= 2 million kg
specific heat = 1000J/kg K
density = 2500kg/m3
Tempmax = 4000K
where should I get started?