Question

Physical properties of various fluids Parameter Density of air Density of oil Density of water Density of mercury Viscosity of air Viscosity of water Ideal gas constant Value Units 1.18 kg/m3 800 kg/m3 1000 kg/m3 13600 kg/m3 0.018 cP 0.89 cP 8.314 J/mol K 28.9g/mol 101.3 kPa Molar mass of air Atmospheric pressure on Earth Question 3 (48 marks) On another consulting job with Intergalactic Engineering you are performing a spacewalk in order to fix a satellite. This means that you are in a specially designed suit to protect you from the harsh environment of space while you repair the satellite. Your space suit is connected to the space shuttle by a tube that is supplying you with fresh air. This tube has a length of 200 m, a diameter of 5 cm, and an absolute roughness of 0.1 cm. The air within your suit and the tube is at 23 "C and 1 atm of pressure. The gas flow is isothermal You The tube supplying you with air The space shuttle Unexpectedly, the tube detaches from the space shuttle. This causes air to leave your suit, travel down the 200 m of the tube, and exit into the vacuum of space. You know that a person loses consciousness when the ambient pressure drops below 0.57 atm. You must reattach your tube to the air supply before the pressure in your suit drops to this point. A. What is the initial velocity at which the gas exits the end of the tube into space? The pressure of space is 1.3x10-14 kPa. (16 marks) B. What is the velocity of the gas exiting the end of the tube into space when the pressure inside the suit is 0.57 atm? (16 marks) C. What is the initial mass flow rate at which gas leaves your suit? Neglect the contribution of kinetic energy to the flow in this calculation (7 marks)

Answer 1

Assumptions : We assume incompressible flow. This is fair because the process is isothermal ( temp is not changing) and volume of suit and tube is not changing. So we can use Bernoulli's principle.

We also assume that velocity of gas inside suit is zero because it is very smaller , almost negligible than velocity of gas escaping from tube. This is because diameter of pipe is very small than the size of suit. Narrow pipe means high speed gas flow . I hope further answers help. :)

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se cond Howing out pe Mau CYDSS SRehon 413.76 x aunea 2 Co.05) 413. X TT avy 3.25 K initial Mau 3.25 K S