Perplexing Thermodynamics problem.Help

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SUMMARY

The discussion revolves around solving a thermodynamics problem involving an air pistol with specific parameters: a cylinder volume of 1 cm³, an initial pressure of 1 MPa, and a temperature of 27°C. The air expands isothermally, and the challenge lies in calculating the final volume, mass of air, work done by the air, and the bullet exit velocity when the pressure drops to 0.1 MPa. The key equations mentioned include the work done by the air, represented as W = ∫ P dV, and the relationship between initial and final states in isothermal processes.

PREREQUISITES
  • Understanding of isothermal processes in thermodynamics
  • Familiarity with the ideal gas law and its applications
  • Knowledge of integration techniques for calculating work done
  • Basic principles of fluid dynamics related to projectile motion
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  • Study the ideal gas law and its implications for isothermal expansion
  • Learn about the integration of pressure-volume work in thermodynamic systems
  • Explore the relationship between work done on a bullet and its exit velocity
  • Investigate isentropic processes and their differences from isothermal processes
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Students of thermodynamics, physics enthusiasts, and anyone involved in mechanical engineering or fluid dynamics who seeks to understand the principles of gas expansion and work calculations in practical applications.

kilroymcb
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This problem has been puzzling me and several classmates for days now. The answer is due monday. I need some help.

"An air pistol contains compressed air in a small cylinder. Assume that the volume is 1 cm^3, pressure is 1 Mpa and the temperature is 27 C when released, the air expands in an isothermal process. If the air pressure is .1 Mpa in the cylinder as the bullet leaves the gun, find A) the final volume and the mass of air B) the work done by the air and the work done on the atmosphere C) the work to the bullet and the bullet exit velocity.

I have no problem with part A, but part B and C pose the problem. Since the mass of the bullet is not given, how can you calculate the work done to the bullet and the bullet exit velocity? I don't even know where to begin.

Help!
 
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Just integrate W = integral P dV for V1 to V2 (which you know both) isohermal expansin PoVo is constant (isentropic expansion is probably more realistic.

Jaap
 

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