Avertical piston/cylinder device with a diameter of 10 cm has a piston with a mass of 100kg and contains 0.2 kg of r-134a. the r-134a is at a pressure of 320 kpa (absolute) and has a quality of 50 percent. what force must be applied to the piston to hold it in place? the local atmospheric pressure is 100 kpa.
a.314 n
b. 747 n
c. 502 n
d. 1013 n
2. what is the initial volume of the piston/cylinder in problem 1?
a. 1.3 l
b . 4.7l
c. 3.6 l
d 6.4l
3. the r-134a in problem 1 is heated until the tempureture is 30 c in a constant pressure process. what is the change in total enthalpy (h) for this process?
a. 24.6 kj
b. 41.7 kj
c.32.8 kj
d. 49.9kj