Physics 182

Transcription

Physics 182
Physics 182: Sample exam questions for Exam 1
Multiple Choice. Choose the one alternative that BEST completes the statement or answers the question, and mark your
scan sheet. Only the scan sheet will be graded.
The correct answers are: C, C, A, C, B, D
1) The diagrams shows a PV diagram for 4.3 g of oxygen gas in a sealed container. The temperature of state 1 is
21°C. What are the temperatures T3 , and T4 ?
A) 16°C and 47°C
B) 11°C and 32°C
C) -52°C and 390°C
D) 220°C and 660°C
2) A gas is initially at (20 Pa, 8 m3) and expands to (27 Pa, 12 m3 ). The minimum amount of pressure the gas can
be under is 9 Pa, and the maximum pressure the gas can be under is 40 Pa. Find the minimum amount of work
that can be done by the gas in going from its initial state to its final state.
A) 180 J
B) 320 J
C) 36 J
D) 160 J
3) A 406.0 kg copper bar is put into a smelter for melting. The initial temperature of the copper is 300.0 K. How
much heat must the smelter produce to completely melt the copper bar? (The specific heat for copper is
386 J/kg·K, the heat of fusion for copper is 205 kJ/kg, and its melting point is 1357 K.)
A) 2.49 × 105 kJ
B) 2.96 × 105 kJ
C) 1.66 × 108 kJ
D) 1.66 × 1011 kJ
4) An ideal gas initially at 300.0 K and occupying a volume of 20.0 L is adiabatically compressed. If its final
temperature is 400.0 K and = 1.3, what is its final volume?
A) 22 L
B) 14 L
C) 7.7 L
D) 52 L
5) 4.8 mol of gas #1 initially has 9000 J of thermal energy. It interacts with 3.4 mol of gas #2, which initially has
5000 J of thermal energy. If both gases are monatomic, what is the change in thermal energy of gas #1?
A) -0.56 kJ
B) -0.80 kJ
C) -0.32 kJ
D) -2.0 kJ
6) What is the efficiency of a Carnot engine operating between a reservoir in which ice and water coexist, and a
reservoir in which water and steam coexist? The pressure is constant at 1.0 atmosphere for both.
A) 100%
B) 1.0%
C) 0.27%
D) 27%
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