Thermodynamics Ideal Gas Problem

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SUMMARY

The discussion focuses on calculating the work done by an ideal gas during an expansion from state (p_1, V_1) to state (p_2, V_2), where p_2 equals 2p_1 and V_2 equals 2V_1. The correct formula for work is identified as W = (p_1 V_1 - p_2 V_2) / (y - 1), with y set to 1.4. A key insight is that the work done corresponds to the area under the pressure-volume curve, which is a straight line in this scenario. The initial attempt at solving the problem was incorrect due to a numerical multiplier error.

PREREQUISITES
  • Understanding of ideal gas laws and properties
  • Familiarity with pressure-volume (P-V) diagrams
  • Knowledge of thermodynamic work calculations
  • Basic grasp of the adiabatic process and the specific heat ratio (y)
NEXT STEPS
  • Study the derivation of work done in isothermal and adiabatic processes
  • Learn how to calculate areas under curves in P-V diagrams
  • Explore the implications of the specific heat ratio (y) in thermodynamic processes
  • Investigate common mistakes in thermodynamic problem-solving
USEFUL FOR

Students studying thermodynamics, physics educators, and anyone involved in solving ideal gas problems in academic or practical settings.

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Homework Statement


An ideal gas expands from the state (p_1, V_1 ) to the state (p_2, V_2 ), where p_2 = 2p_1 and V_2 = 2V_1. The expansion proceeds along the straight diagonal path AB shown in the figure.

Find an expression for the work done by the gas during this process.
Express your answer in terms of the variables p_1 and V_1.


Homework Equations


W = (p_1 V_1 - p_2 V_2) / (y - 1)

The Attempt at a Solution


I put the equation exactly with y = 1.4.
Masteringphysics says "Your answer either contains an incorrect numerical multiplier or is missing one.".

What have I done wrong?
 
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Is that an equation from a textbook? Don't think about trying to apply an equation. Instead, use theory and some common sense.

You state in the problem that there is a figure that you don't show. It does sound like you have a pressure vs volume plot where there is a straight line from p1,V1 to p2,V2.

With that, work is basically the area under that line. Calculate that area for work.
 
I have managed to solve this problem. Thank you.
 

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