Physics, 24.07.2019 20:10 queenkimm26

9.96 kg of r-134a at 300 kpa fills a rigid container whose volume is 14 l. determine the temperature and total enthalpy in the container. the container is now heated until the pressure is 600 kpa. determine the temperature and total enthalpy when the heating is completed. use data from the steam tables.

Answers: 1

Show answers

Answers

Answer from: tacojordan4128

At 300 kPa: The temperature is 0.529 ºC and the total enthalpy, 2016.77kJ.

At 600 kPa: The temperature is 21.45 ºC and the total enthalpy, 2317.00 kJ.

Explanation:

1. Get the container volume in cubic meters: $1m^{3}=1000L$

$V=14L*\frac{1m^{3}}{1000L} =0.014m^{3}$

2. Find the specific volume of R-134a:

$v=\frac{V}{m}=\frac{0.014m^{3}}{9.96kg}=0.001416\frac{m^{3}}{kg}$

3. Find the phase of R-134a, for this, look at the steam tables (Note: I am using the table B.5.1 from van Wylen 6th Edition.) Look for a pressure of 300 kPa at the table; I found this values:

T(ºC) P(kPa) vf( $\frac{m^{3}}{kg}$ vg( $\frac{m^{3}}{kg}$

0 294.0 0.000773 0.06919

5 350.9 0.000783 0.05833

It is possible to predict that the properties of saturated R134-a at 300 kPa would be so closely to that of 294 kPa. From that data we find that the specific volume of our R134-a is between vf and vg, so we conclude that it is a vapor liquid mixture.

4. Find the quality (x)

From a linear interpolation for the pressure, it is possible to know the saturation data for 300 KPa:

T(ºC) P(kPa) vf( $\frac{m^{3}}{kg}$ vg( $\frac{m^{3}}{kg}$

0.529 300 0.0007405 0.06796

Applying the quality relation for specific volume:

$v=v_{f}+xv_{fg}\\x=\frac{v-v_{f}}{v_{fg}}\\x=0.009989$

The total enthalpy is calculated in the same way:

$h=h_{f}+xh_{fg}\\h=200.71+0.00898*197.96=202.48 \frac{kJ}{kg}$

H=202.48*9.96=2016.77kJ

The temperature is 0.529 ºC and the total enthalpy, 2016.77kJ.

When the substance is heated, the volume remains constant because the container is rigid, so the calculation requires to do the same process again with 600 kPa.

T(ºC) P(kPa) vf( $\frac{m^{3}}{kg}$ vg( $\frac{m^{3}}{kg}$

21.45 600 0.000820 0.03458

hf( $\frac{kJ}{kg}$ hg( $\frac{kJ}{kg}$

229.56 406.13

x=0.0173

$h=232.63 \frac{kJ}{kg}$

H=m*h=2317.00kJ

The temperature is 21.45 ºC and the total enthalpy, 2317.00 kJ.

Answer from: Quest

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27

Answer from: Quest

c) up is the direction the magnetic force is acting on the charge.

Another question on Physics

Physics, 22.06.2019 07:30

Identify the theory that can be used to explain each phenomenon. answers diffraction: wave theory interference: wave theory reflection: both particle and wave theories refraction: both particle and wave theories

Answers: 3

Answer

Physics, 22.06.2019 08:30

Hey student studies gravity using objects that have the same mass which two objects have the greatest gravitational force acting between them a. 100kg 1.0m 100kg b. 100kg 2.0m 100kg c. 100kg 2.0m 100kg big d. 100kg big 3.0m 100kg big

Answers: 1

Answer

Physics, 22.06.2019 12:30

Urgent pls a. coal consumption levels off and remains flat. b. petroleum, natural gas, and renewables show an increase in consumption c. more nonrenewable resources continued to be consumed than renewable. d. there is little projected increase in nuclear energy use. e. carbon dioxide emissions are projected to decline as we approach 2040. global energy consumption is defined as the total energy used by an individual or organizations from around the world. use the graph above to analyze the projected energy consumption from now until 2040. which statements in the prompt apply? a) a, b, d b) b, c, d c) a, c, d d) a, b, c, d

Answers: 1

Answer

Physics, 22.06.2019 21:20

An electron is ejected into a horizontal uniform e⃗ field at a parallel horizontal velocity of v0. assume the electron's initial position x0, initial velocity v0, time t, magnitude of electric field e, electron's mass m, and the magnitude of the electron's charge |e|. ignore the force that earth exerts on the electron. assume the e⃗ field is in the same direction as the initial velocity. part a define the equation for the electron's velocity. express your answer in terms of the variables v0, |e|, t, e, and m.

Answers: 3

Answer

You know the right answer?

9.96 kg of r-134a at 300 kpa fills a rigid container whose volume is 14 l. determine the temperature...

Questions