1. List three ways the Earth was different today from when it was first formed.

Water, initially saturated vapor at 4 bar, fills a closed, rigid container. The water is heated until its temperature is 360°C.

salantis [7]

Explanation:

Using table A-3, we will obtain the properties of saturated water as follows.

Hence, pressure is given as p = 4 bar.

$u_{1} = u_{g}$ = 2553.6 kJ/kg

$v_{1} = v_{g} = 0.4625 m^{3}/kg$

At state 2, we will obtain the properties. In a closed rigid container, the specific volume will remain constant.

Also, the specific volume saturated vapor at state 1 and 2 becomes equal. So, $v_{2} = v_{g} = 0.4625 m^{3}/kg$

According to the table A-4, properties of superheated water vapor will obtain the internal energy for state 2 at $v_{2} = v_{g} = 0.4625 m^{3}/kg$ and temperature $T_{2} = 360^{o}C$ so that it will fall in between range of pressure p = 5.0 bar and p = 7.0 bar.

Now, using interpolation we will find the internal energy as follows.

$u_{2} = u_{\text{at 5 bar, 400^{o}C}} + (\frac{v_{2} - v_{\text{at 5 bar, 400^{o}C}}}{v_{\text{at 7 bar, 400^{o}C - v_{at 5 bar, 400^{o}C}}}})(u_{at 7 bar, 400^{o}C - u_{at 5 bar, 400^{o}C}})$

$u_{2} = 2963.2 + (\frac{0.4625 - 0.6173}{0.4397 - 0.6173})(2960.9 - 2963.2)$

= 2963.2 - 2.005

= 2961.195 kJ/kg

Now, we will calculate the heat transfer in the system by applying the equation of energy balance as follows.

Q - W = $\Delta U + \Delta K.E + \Delta P.E$ ......... (1)

Since, the container is rigid so work will be equal to zero and the effects of both kinetic energy and potential energy can be ignored.

$\Delta K.E = \Delta P.E$ = 0

Now, equation will be as follows.

Q - W = $\Delta U + \Delta K.E + \Delta P.E$

Q - 0 = $\Delta U + 0 + 0$

Q = $\Delta U$

Now, we will obtain the heat transfer per unit mass as follows.

$\frac{Q}{m} = \Delta u$

$\frac{Q}{m} = u_{2} - u_{1}$

= (2961.195 - 2553.6)

= 407.595 kJ/kg

Thus, we can conclude that the heat transfer is 407.595 kJ/kg.

4 0

2 years ago

A 0.50-g sample of vegetable oil is placed in a calorimeter. when the sample is burned, 18.9 kj is given off. what is the energy

just olya [345]

First of all, we need to convert the energy produced from kilojoules to calories. 1 kJ corresponds to 239.1 cal, therefore:

$E=18.9 kJ \cdot 239.1 =4519.4 cal$

And so now we can calculate the energy value of the oil:

$E_v = \frac{E}{m}=\frac{4519.4 cal}{0.50 g}=9038.8 cal/g$

8 0

3 years ago

A car traveling 13m/s to the north collideswith a car traveling 19m/s to the south. Each car has a mass of 1250 kg. If the syste

GalinKa [24]

Let P1=13m/s(1250kg)=16250 kg m/s (positive velocity is north here)
P2=-19m/s(1250kg)=-23750 kg m/s
Total system momentum is P1 + P2 = 16250 - 23750 = -7500 (negative momentum is south pointing).
Due to the conservation of momentum, this is also the final momentum and we see the two cars have a mass of 1250 + 1250 = 2500kg and have a velocity
-7500 = 2500kg * Vfinal
Final = -3m/s (moving southward)
Each car's momentum changes from the initial value it had to this final value, but the total system momentum does not change, due to the conservation law.

5 0

3 years ago

Read 2 more answers

_____ Is a process that invloves the collection of information and ideas supported by evidence

zalisa [80]

Answer:

Science - is a process that involves the collection of information and ideas supportedby evidence.

6 0

2 years ago

Read 2 more answers

Which statement accurately describes what happens when water turns to ice in terms of energy

Deffense [45]

Answer:

The water releases energy which causes the water molecules to have less kinetic and potential energy, changing their configuration from liquid to solid.

Explanation:

Confirmed through test.

7 0

3 years ago