Question

Consider a transformation from point A to B in a two-step process. First, the pressure is lowered from 3 MPa at point A to a pressure of 1 MPa, while keeping the volume at 2 L by cooling the system. The state reached is labeled C. Then the system is heated at a constant pressure to reach a volume of 6 L in the state B. (a) Find the amount of work done on the ACB path.

a. Positive
b. Negative
c. Zero
d. Cannot be determined

Answer 1

The amount of work done on the ACB path is negative.

Step-by-step explanation:

The amount of work done on the ACB path can be determined by calculating the area under the curve in the pV plane. In this case, the work done is equal to the area enclosed by the path ACB.

Since the pressure is lowered from 3 MPa to 1 MPa, the work done is negative because the system is doing work on the surroundings. Therefore, the correct answer is b. Negative.