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A well insulated rigid container of volume 1 m3 contains 1.0 kg of an ideal gas [Cp = 1000 J/(kg.K) and Cv = 800 J/(kg.K)] at a pressure of 105 Pa. A stirrer is rotated at constant rpm in the container for 1000 rotations and the applied torque is 100 N-m. The final temperature of the gas (in K) is _________.
(Important - Enter only the numerical value in the answer)
    Correct answer is '1128.31'. Can you explain this answer?
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    Given data:
    - Volume of the container (V) = 1 m^3
    - Mass of the gas (m) = 1.0 kg
    - Specific heat at constant pressure (Cp) = 1000 J/(kg.K)
    - Specific heat at constant volume (Cv) = 800 J/(kg.K)
    - Pressure of the gas (P) = 105 Pa
    - Applied torque (T) = 100 N-m
    - Number of rotations of the stirrer (N) = 1000

    Assumptions:
    - The gas behaves as an ideal gas.
    - The process is adiabatic (no heat exchange with the surroundings).
    - The process is reversible.
    - The gas is in thermal equilibrium throughout the process.

    Process:
    1. Calculate the work done by the stirrer using the formula:
    Work (W) = Torque (T) × Number of rotations (N)

    2. Use the ideal gas equation to find the initial temperature (T1) of the gas:
    PV = mRT1
    R = Cp - Cv (gas constant for an ideal gas)
    T1 = PV / (mR)

    3. Determine the change in internal energy (ΔU) using the first law of thermodynamics:
    ΔU = Q - W
    Q = 0 (adiabatic process, no heat exchange)
    ΔU = -W

    4. Calculate the change in temperature (ΔT) using the equation:
    ΔU = mCvΔT
    ΔT = ΔU / (mCv)

    5. Determine the final temperature (T2) of the gas:
    T2 = T1 + ΔT

    Calculation:
    1. Work done by the stirrer:
    W = T × N = 100 N-m × 1000 rotations = 100,000 N-m

    2. Ideal gas equation:
    R = Cp - Cv = 1000 J/(kg.K) - 800 J/(kg.K) = 200 J/(kg.K)
    T1 = PV / (mR) = (105 Pa × 1 m^3) / (1.0 kg × 200 J/(kg.K)) = 0.525 K

    3. Change in internal energy:
    ΔU = -W = -100,000 N-m

    4. Change in temperature:
    ΔT = ΔU / (mCv) = (-100,000 N-m) / (1.0 kg × 800 J/(kg.K)) = -125 K

    5. Final temperature:
    T2 = T1 + ΔT = 0.525 K - 125 K = -124.475 K

    Conclusion:
    The final temperature of the gas is approximately -124.475 K. However, this result is not physically meaningful because a negative temperature is not possible. It is likely that there was an error in the calculation or some assumption made in the problem statement.
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    A well insulated rigid container of volume 1 m3 contains 1.0 kg of an ...
    No my dear correct ans is 1285.39 K
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    A well insulated rigid container of volume 1 m3 contains 1.0 kg of an ideal gas [Cp = 1000J/(kg.K) and Cv = 800 J/(kg.K)] at a pressure of 105 Pa. A stirrer is rotated at constant rpm inthe container for 1000 rotations and the applied torque is 100 N-m. The final temperature ofthe gas (in K) is _________.(Important - Enter only the numerical value in the answer)Correct answer is '1128.31'. Can you explain this answer?
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