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

Light that is polarized along the vertical direction is incident on a sheet of polarizing material. only 96% of the intensity of the light passes through the sheet and strikes a second sheet of polarizing material. no light passes through the second sheet. what angle does the transmission axis of the second sheet make with the vertical?

Using the free-body diagram, calculate the net force acting on the sled. is the sled in a state of dynamic equilibrium?

You are a researcher for a golf club manufacturer. you are given two identical looking cubes of a metal alloy. you are informed that they are made of the exact same material, but one is crystalline, whereas the other is amorphous. it is your job to determine which one is amorphous this one is more stress-resistant and is useful in reinforcing golf clubs. which of the following is the best way to determine which is which? a. determine the density of each cube. the more dense one is the amorphous solid. b. melt both cubes and look for a broader range of melting temperatures. the one that melts over a broader range of temperatures is the amorphous solid. c. determine the density of each cube. the less dense cube is the amorphous solid. d. melt both cubes and measure the range of melting temperatures. the one that melts over a narrower range of temperatures is the amorphous solid.