Consider the following processes: I. Energy flows as heat....

In summary: Another requirement is that there be only one reservoir to supply heat (and no reservoir to remove heat). This is basically the Kelvin statement of the 2nd law.
  • #1
Any Help
79
2

Homework Statement



Consider the following processes: I. Energy flows as heat from a hot object to a colder object II. Work is done on a system and an equivalent amount of energy is rejected as heat by the system III. Energy is absorbed as heat by a system and an equivalent amount of work is done by the system .Which are never found to occur?
A. Only I
B. Only II
C. Only III
D. Only II and III
E. I, II, and III
ans: C

Homework Equations

The Attempt at a Solution


Why its C??
 
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  • #2
Any Help said:

Homework Statement



Consider the following processes: I. Energy flows as heat from a hot object to a colder object II. Work is done on a system and an equivalent amount of energy is rejected as heat by the system III. Energy is absorbed as heat by a system and an equivalent amount of work is done by the system .Which are never found to occur?
A. Only I
B. Only II
C. Only III
D. Only II and III
E. I, II, and III
ans: C

Homework Equations

The Attempt at a Solution


Why its C??
It is wrong. That's why.
 
  • #3
Chestermiller said:
It is wrong. That's why.
I mean why it is wrong?
 
  • #4
Any Help said:
I mean why it is wrong?
This is the same thing as an isothermal expansion, which you can always do. What they erroneously neglected to consider is this can never be done for a system operating in a cycle using a single (isothermal) reservoir.
 
  • #5
Any Help said:
I mean why it is wrong?
It looks like whoever wrote the question is using the word system to mean heat engine. Try calculating the efficiency of the described engine.
 
  • #6
vela said:
It looks like whoever wrote the question is using the word system to mean heat engine. Try calculating the efficiency of the described engine.
Another requirement is that there be only one reservoir to supply heat (and no reservoir to remove heat). This is basically the Kelvin statement of the 2nd law.
 

Related to Consider the following processes: I. Energy flows as heat....

1. What is the meaning of "energy flows as heat" in this context?

"Energy flows as heat" refers to the transfer of energy from one system to another in the form of heat. This transfer occurs when there is a temperature difference between the two systems.

2. How does energy flow as heat affect the surrounding environment?

Energy flow as heat can have various effects on the surrounding environment, depending on the amount of energy being transferred and the specific system in question. In general, it can result in changes in temperature, chemical reactions, and physical changes such as melting or evaporation.

3. Can energy flow as heat be reversed?

Yes, energy flow as heat can be reversed. This process is known as heat transfer and occurs when heat flows from a warmer system to a cooler system, resulting in a decrease in temperature of the warmer system and an increase in temperature of the cooler system.

4. Are there any limitations to energy flow as heat?

There are certain limitations to energy flow as heat, most notably the second law of thermodynamics. This law states that heat always flows spontaneously from a hotter system to a cooler system, and it is impossible for heat to flow in the opposite direction without the input of external energy.

5. How does energy flow as heat play a role in everyday life?

Energy flow as heat is a fundamental process in everyday life. It is responsible for regulating Earth's climate, powering our homes and vehicles, and even aiding in digestion and metabolism in living organisms. Without energy flow as heat, life as we know it would not be possible.

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