FiltersDone

Question type

Essay

Multiple Choice

Short Answer

True False

Matching

Exam 20: Second Law of Thermodynamics

Show Answer

Share

---

All types

Filters

Study Flashcards

Question 21

Essay

Review LaterAdd Note

Review Later

On a hot day, you open the refrigerator and experience a refreshing feeling when the cool air comes in contact with your body. You think to yourself "I think that I'll just keep the refrigerator door open and stand in front of the refrigerator all day today to stay cool. I might even bring a chair." Will this work? Explain why or why not.

Correct Answer

verified

This will not work because the refrigera...

View Answer

Show Answer

Question 22

Essay

Review LaterAdd Note

Review Later

FIGURE 20-2 -A monatomic ideal gas reversibly follows the process shown in Fig. 20-2 starting from state A at a temperature 300 K and ending at state B. (a) What is the final temperature of the gas? (b) What is the change in internal energy of the gas in going from state A to state B? (c) What is the change in entropy of the gas in going from state A to state B?

Correct Answer

verified

(a) 3680 K...

View Answer

Show Answer

Question 23

Essay

Review LaterAdd Note

Give the Kelvin-Planck statement of the Second Law of Thermodynamics.

A heat pump has a coefficient of performance that is 60% of the Carnot heat pump coefficient of performance. The heat pump is used to heat a home to 24.0°C during the winter with the low temperature reservoir at the outdoor temperature. At which outdoor temperature would it be more efficient to add the energy directly to the interior of the home than use it to run the heat pump?

Describe the Carnot cycle.

Which has the larger entropy: a gas that occupies only half of a container, with the other half a vacuum, or the same gas occupying the entire container?

A Carnot cycle engine operates between a low temperature reservoir at 20°C and a high temperature reservoir at 800°C. If the engine is required to output 20.0 kJ of work per cycle, how much heat must the high temperature reservoir transfer to the engine during each cycle?

Sketch the schematic diagram of energy transfers for a heat engine.

Explain the following statement: "In any natural process, some energy becomes unavailable to do useful work."

An air conditioner with a coefficient of performance of 3.5 uses 30 kW of power. How much power is it discharging to the outdoors?

Give the Clausius statement of the Second Law of Thermodynamics.

A heat engine operating at maximum efficiency has an efficiency of 35.0%. The temperature of the hot reservoir is 700 K. What is the temperature of the cold reservoir?

Heat will flow spontaneously from a cold object to a hot object.

In any natural process, some energy becomes unavailable to do useful work.

A refrigerator has a coefficient of performance equal to 4.2. How much work must be done on the refrigerator in order to remove 250 J of heat from the interior?

All reversible engines operating between the same two temperatures have the same efficiency.

A Carnot cycle consists of

What is the coefficient of performance of a Carnot heat pump used to remove heat from ice at 0.0°C and add heat to a room at 20.0°C?

A heat engine with an efficiency of 30.0% performs 2500 J of work. How much heat is discharged to the lower temperature reservoir?

Natural processes tend to move toward a state of less disorder.