THE PRACTICE STUDIO
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PRACTICE / Cyclic processes
Use the loop direction and area
A gas follows A→B→C→D→A on straight p–V legs. The states (V, p) are A = (1 L, 2 kPa), B = (1 L, 5 kPa), C = (4 L, 5 kPa), D = (4 L, 2 kPa).
| State | Volume (L) | Pressure (kPa) |
|---|---|---|
| A | 1 | 2 |
| B | 1 | 5 |
| C | 4 | 5 |
| D | 4 | 2 |
Find the net heat absorbed by the gas over the cycle.
Organize the givens & assumptions
- High/low pressures: 5/2 kPa
- High/low volumes: 4/1 L
- Path A→B→C→D→A
Quasistatic paths, only pressure-volume work, and positive work done by the gas; the gas returns to its initial state.
- A
- B
- C
- D
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