Question

The mole number is 4.

The Cycle starts at the upper left corner A at a temperature

Of 200 K and expands at

constant pressure of 5x10⁴ N/m² to state B at the upper right

with a temperature of 400 K; then

decreases at constant volume to a pressure of 2.5x10⁴ N/m² and temperature 200 K

at state C on the lower right . and from there compressed at

constant pressure to point D in the lower left at a temperature of 100 K. From D it increases the pressure at constant volume back to A. Thus it has completed a cycle ABCDA.

1. Find the volumes at the corners A, B, C and D using the gas law equation PV= nRT

2. Find the work done for each path of the cycle and the net work of the cycle

3. Determine which parts of the cycle give positive heat and compute them using formulas for Q_P and Q_V.

4. Find the internal energy U at state A and B and its change.

5. If we use this cycle to operate an engine, what is the input heat?

6. What is the efficiency of the engine?      

Answer 1