Mathematical and Physical Journal
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Problem P. 4451. (May 2012)

P. 4451. A sample of diatomic, ideal gas is taken through a cyclic process. The cyclic process can be composed of such open processes that the specific heat capacity of the gas during the certain processes does not change. The cyclic process is shown in the graph of the figure. The algebraic sum of the absorbed and delivered heat by the gas up to an instantaneous state, (Q), is shown on the horizontal axis, and the total amount of work done by the gas on its environment up to reaching the certain instantaneous state, (W*), is shown on the y axis.

a) Using the graph, determine the efficiency of the cyclic process.

b) What types of processes build up the cyclic process? Reason your statements.

c) Let the pressure of the gas at state 1 be p0, and its volume be V0. Using these parameters plot the cyclic process on the p-V diagram.

(5 pont)

Deadline expired on June 11, 2012.


Sorry, the solution is available only in Hungarian. Google translation

Megoldásvázlat. a) 16,4%.

b) 1\rightarrow2 és 3\rightarrow4 izochor folyamatok, mert ezek során a gáz nem végez munkát. A 2\rightarrow3 és 4\rightarrow1 folyamatokban Q=\frac{7}{2}W^*, ez a kétatomos gáz izobár állapotváltozásánál teljesül.

c) A megadott adatok szerint p0V0 nagysága 80 J kell legyen.


Statistics:

54 students sent a solution.
5 points:Agócs Fruzsina, Antalicz Balázs, Barta Szilveszter Marcell, Bolgár Dániel, Buttinger Milán, Csáky Pál, Csathó Botond, Cseuz Áron, Csóka József, Czigány Máté Gábor, Czipó Bence, Dávid Bence, Fehér Zsombor, Fekete Panna, Filep Gábor, Fonyó Viktória, Garami Anna, Horicsányi Attila, Kollarics Sándor, Laczkó Zoltán Balázs, Nagy Zsolt, Sárvári Péter, Seres Imre, Seress Dániel, Szabó 928 Attila, Szélig Áron, Szigeti Bertalan György, Szilágyi 585 Dezső, Szilágyi András, Vajda Balázs, Varju Ákos, Virágh Anna.
4 points:Bingler Arnold, Büki Máté, Emri Tamás, Epinger Bálint, Huszár Emese, Juhász Péter, Koncz Gabriella, Olosz Balázs, Pázmán Zalán, Váncsa Szilárd.
3 points:5 students.
2 points:7 students.

Problems in Physics of KöMaL, May 2012