- #1
thenewbosco
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an air rifle shoots a lead pellet by allowing high pressure gas to expand.
This happens quickly so it is an adiabatic process. initially 12 cubic centimeters of air are admitted to the barrel. It behaves as an ideal gas, [tex]\gamma = 1.40[/tex]. The air expands behind a 1.1 g pellet and pushes on it as a piston with cross sectional area 0.03 cm^2. the pellet emerges from the barrel with speed 120 m/s.
I am to use the work gone by the gas:
[tex] W = (\frac{1}{\gamma - 1})(PiVi - PfVf)[/tex]
to calculate the initial pressure required.
I do not know though how to find the final volume and final pressure...
I thought to use [tex]PfVf^\gamma = PiVi^\gamma[/tex] but this does not seem to change anything for me i still need to know Vf...
any help on this...thanks
This happens quickly so it is an adiabatic process. initially 12 cubic centimeters of air are admitted to the barrel. It behaves as an ideal gas, [tex]\gamma = 1.40[/tex]. The air expands behind a 1.1 g pellet and pushes on it as a piston with cross sectional area 0.03 cm^2. the pellet emerges from the barrel with speed 120 m/s.
I am to use the work gone by the gas:
[tex] W = (\frac{1}{\gamma - 1})(PiVi - PfVf)[/tex]
to calculate the initial pressure required.
I do not know though how to find the final volume and final pressure...
I thought to use [tex]PfVf^\gamma = PiVi^\gamma[/tex] but this does not seem to change anything for me i still need to know Vf...
any help on this...thanks