An insulated, constant-volume system containing 1.36 kg of air receives 53 kJ of paddle work. The initial temperature is 27 ∘ C. Determine a) the change of internal energy. b) the final temperature. Assume a mean value C. = 0.718 kJ/kgK.

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An insulated, constant-volume system containing 1.36 kg of air receives 53 kJ of paddle work. The initial temperature is       27    ∘    C. Determine a) the change of internal energy. b) the final temperature. Assume a mean value C. = 0.718 kJ/kgK.

Sauppypefpg · Accepted Answer

Given Initial temperature       T    1    =      27    ∘    C  =  27  +  273  =  300     Kmass  m  =  1.36Work done W =−53 kJ (since it is externally input work)Let       T    2   be the final temperature       C    V    =  0.718   kJ/Kg KFrom the first law of thermodynamics dU= dQ− W It is an insulated system no heat transfer takes placeso dQ = 0dU =− WdU = 53 kJdU is the change in internal energy. We know that Change in internal energy is given by dU = mCvdT  53  =  1.36  ⋅  0.718  (      T    2    −      T    1    )    −  53  =  0.97648  (      T    2    −  300  )    54.2766  =      T    2    −  300        T    2    =  345.2766     K  =      81.2766    ∘    Ca) the final temperature = 81.266 degree celsiusb) Change in internal energy dU = 53 kJ

An insulated, constant-volume system containing 1.36 kg of air receives 53 kJ of paddle work. The initial temperature is 27°C. Determine a) the change of internal energy. b) the final temperature. Assume a mean value C. = 0.718 kJ/kgK.

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