Heating a Cabaret during the winter

  • Thread starter Thread starter Dreebs
  • Start date Start date
  • Tags Tags
    Heating Thermal
Dreebs
Messages
25
Reaction score
1

Homework Statement


During the winter, your climate control system must begin warming the cabaret air so that the cabaret air is hotter than outdoor air. Amazingly enough, it can do this relatively efficiently by transferring heat from the outside air into the cabaret. However, your system must use electricity to carry out this heat transfer. Why won't the heat transfer occur naturally?
Select one:
a. Heat tends to flow naturally from inside to outside. Transporting heat against its natural direction of flow requires the consumption of ordered energy.
b. Although heat tends to flow from hotter to colder, moving that heat from place to place requires the conversion of ordered energy (such as electricity) into thermal energy.
c. Heat doesn't flow naturally from cold to hot because that would produce a decrease in entropy.
d. As each joule of heat moves from the colder outdoor air to the warmer cabaret air, the entropy of the cabaret air increases by more than the entropy of the outdoor air decreases. To obtain that increase in entropy, some electrical energy must be converted to thermal energy.

Homework Equations


N/A

The Attempt at a Solution


D, because in A, heat does not naturally flow from inside to outside. In B, heat should tend to flow from hot to cold regardless of electrical energy. In C, heat does flow from hot to cold leaving that one completely wrong. This leaves D, as it is the only one that makes sense I believe.
 
Dreebs said:
In C, heat does flow from hot to cold leaving that one completely wrong.
Read C more carefully.
 
haruspex said:
Read C more carefully.
Whoops! Somehow read it backwards. With that change, would that then make C the correct answer since heat doesn't flow naturally from cold to hot.
 
Dreebs said:
Whoops! Somehow read it backwards. With that change, would that then make C the correct answer since heat doesn't flow naturally from cold to hot.
Right.
 
  • Like
Likes   Reactions: Dreebs
Thanks for your help!
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 14 ·
Replies
14
Views
5K
Replies
1
Views
3K
Replies
77
Views
24K
  • · Replies 4 ·
Replies
4
Views
4K