# A piston/cylinder assembly contains 2 kg of liquid water

Chapter 3, Problem 48HP

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QUESTION:

Problem 48HP

A piston/cylinder assembly contains 2 kg of liquid water at 20°C and 300 kPa, as shown in Fig. P3.48. There is a linear spring mounted on the piston such that when the water is heated, the pressure reaches 3 MPa with a volume of 0.1 m3.

a. Find the final temperature.

b. Plot the process in a Pv diagram.

c. Find the work in the process.

FIGURE P3.48

QUESTION:

Problem 48HP

A piston/cylinder assembly contains 2 kg of liquid water at 20°C and 300 kPa, as shown in Fig. P3.48. There is a linear spring mounted on the piston such that when the water is heated, the pressure reaches 3 MPa with a volume of 0.1 m3.

a. Find the final temperature.

b. Plot the process in a Pv diagram.

c. Find the work in the process.

FIGURE P3.48

Solution 48HP

Step 1 of 3

Part a

We are required to calculate the final temperature for the process.

For water at 200 C, from table B.1.1, the saturated liquid specific volume is m3/kg

The final volume of water is m3

The final specific volume of water is

m3/kg

m3/kg

The corresponding temperature at 3 MPa or 3000 kPa from table B.1.3 is 233.900 C.