A closed, rigid tank contains Refrigerant 134a, initially at $100^{\circ} \mathrm{C}$. The refrigerant is cooled until it becomes saturated vapor at $20^{\circ} \mathrm{C}$. For the refrigerant, determine the initial and final pressures, each in bar, and the heat transfer, in kJ/kg. Kinetic and potential energy effects can be ignored.

A piston–cylinder assembly containing water, initially a liquid at $50^{\circ} \mathrm{F}$, undergoes a process at a constant pressure of 20 $\text{lbf/in.}^{2}$, to a final state where the water is a vapor at $300^{\circ}\text{F}$ Kinetic and potential energy effects are negligible. Determine the work and heat transfer, in Btu per lb, for each of three parts of the overall process: (a) from the initial liquid state to the saturated liquid state, (b) from saturated liquid to saturated vapor, and (c) from saturated vapor to the final vapor state, all at 20 $\mathrm{lbf}/\mathrm{in}.^{2}$.

A well-insulated, rigid tank contains 1.5 kg of Refrigerant 134A, initially a two-phase liquid–vapor mixture with a quality of 60$\%$ and a temperature of $0^{\circ} \mathrm{C}$. An electrical resistor transfers energy to the contents of the tank at a rate of 2 kW until the tank contains only saturated vapor. For the refrigerant, locate the initial and final states on a $T-v$ diagram and determine the time it takes, in s, for the process.

Refrigerant 134a initially at $-36^{\circ} \mathrm{C}$ fills a rigid vessel. The refrigerant is heated until the temperature becomes $25^\circ C$ and the pressure is 1 bar. There is no work during the process. For the refrigerant, determine the heat transfer per unit mass and the change in specific exergy, each in kJ/kg. Comment. Let $T_{0}=20^{\circ} \mathrm{C}, p_{0}=0.1 \mathrm{MPa}.$

A 0.5-m^3 rigid tank contains refrigerant-134a initially at 200 kPa and 40 percent quality. Heat is transferred now to the refrigerant from a source at 35$^\circ{}$C until the pressure rises to 400 kPa. Determine (a) the entropy change of the refrigerant, (b) the entropy change of the heat source, and (c) the total entropy change for this process.

Determine whether each set is finite or infinite.

$$\{ x | x \in \mathbf { N } \text { and } x < 50,000 \}$$

It is estimated that the net amount of carbon dioxide fixed by photosynthesis on the landmass of Earth is $5.5 \times 10 ^ { 16 } \mathrm { g } / \mathrm { yr }$ of $CO_2.$ Assume that all this carbon is converted into glucose. Calculate the average rate of conversion of solar energy into plant energy in megawatts, MW (1W = 1 J/ s). A large nuclear power plant produces about $10^3$ MW. The energy of how many such nuclear power plants is equivalent to the solar energy conversion?

Refrigerant-134a enters the compressor of a refrigeration system as saturated vapor at 0.14 MPa and leaves as superheated vapor at 0.8 MPa and 60$^\circ{}$C at a rate of 0.06 kg/s. Determine the rates of energy transfers by mass into and out of the compressor. Assume the kinetic and potential energies to be negligible.

A $0.06-m^{3}$ rigid tank initially contains refrigerant-134a at 0.8 MPa and 100 percent quality. The tank is connected by a valve to a supply line that carries refrigerant-134a at 1.2 Mpa and $36^{\circ} \mathrm{C}$. Now the valve is opened, and the refrigerant is allowed to enter the tank. The valve is closed when it is observed that the tank contains saturated liquid at 1.2 MPa. Determine (a) the mass of the refrigerant that has entered the tank and (b) the amount of heat transfer.

Determine the values of the specified properties at each of the following conditions and show the states on a sketch of the $T-\upsilon$ diagram. (a) For Refrigerant 22 at $p=60 \: \mathrm{lbf} / \mathrm{in} .^{2}$ and $u=50 \: \mathrm{Btu} / \mathrm{b}$, determine T in $^{\circ} \mathrm{F}$ and $\upsilon$ in $\mathrm{ft}^{3} / \mathrm{lb}$. (b) For Refrigerant 134a at $T=120^{\circ} \mathrm{F}$ and $u=114 \:\mathrm{Btu/lb}$, determine T in $^{\circ} \mathrm{F}$ and $\upsilon$ in $\mathrm{ft}^{3} / \mathrm{lb}$ . (c) For water vapor at $p=100 \: \mathrm{lbf/in}^{2}$ and $h=1240 \: \mathrm{Btu} /lb$ determine T in $^{\circ} \mathrm{F}, v$ in $\mathrm{ft}^{3} / \mathrm{lb},$ and $\upsilon$ in $\mathrm{Btu} / \mathrm{b}$.

A closed, rigid tank contains a two-phase liquid–vapor mixture of Refrigerant 22 initially at $-20^{\circ} \mathrm{C}$ with a quality of 50.36$\%$. Energy transfer by heat into the tank occurs until the refrigerant is at a final pressure of 6 bar. Determine the final temperature, in $^{\circ} C$. If the final state is in the superheated vapor region, at what temperature, in $^{\circ} C$, does the tank contain only saturated vapor?

A rigid, insulated tank contains 0.5 kg of carbon dioxide, initially at 15 kPa, $20^{\circ} \mathrm{C}.$ The carbon dioxide is stirred by a paddle wheel until its pressure is 200 kPa. Using the ideal gas model with $c_{v}=0.65 \mathrm{kJ} / \mathrm{kg} \cdot \mathrm{K},$ determine, in kJ, (a) the work, (b) the change in exergy of the carbon dioxide, and ( c) the amount of exergy destroyed. Ignore the effects of motion and gravity, and let $T_{0}=20^{\circ} \mathrm{C}, p_{0}=100 \mathrm{kPa}.$

Water, initially saturated vapor at 4 bar, fills a closed, rigid container. The water is heated until its temperature is $400^{\circ} \mathrm{C}$. For the water, determine the heat transfer, in kJ per kg of water. Kinetic and potential energy effects can be ignored.

What is the y-intercept of 60x+55y=660?