# Questions...Not as much

by Security
Tags: questionsnot
 P: 59 On a hot day, it is 90 degrees in your friend Eustace's kitchen. Eustace decides to close all the doors and windows so no further heat transfer occurs between the outdoors and his apartment, and then he opens his refrigerator. Will the refrigerator cool down the kitchen? Why or why not? Describe the flow of hear in the room after the refrigerator door is opened. (My Teacher says not to consider the windows for this questions and the additional questions that follow.) A.) After 5 minutes, would the air in the refrigerator be changing temperature less quickly, more quickly, or at the same rate as it did when the refrigerator's door was first opened? Why? (Btw, all my answers to these questions were wrong and long, so thats why I am not posting the them. My Answer: It would be changing more quickly because it would now be trying to draw the energy out of objects in the kitchen to make it cold. B.) If the refrigerator is unplugged, what will eventually happen to the flow of heat in the room? My Answer: it would only come from the window, not from refrigerator coils. Rethought Question it might be: 'the hear would flow throught the room until it reaches a thermal equilibrium.'
Emeritus
PF Gold
P: 10,427
 Originally posted by Security Will the refrigerator cool down the kitchen? Why or why not?
If no heat flow occurs between his apartment and the outside world, then there is no way the room can get colder. The refrigerator cools down the space inside it and dumps the waste heat to the room. Because it's not 100% efficient, it actually exhausts more heat into the room than it removes from the space inside it.
 A.) After 5 minutes, would the air in the refrigerator be changing temperature less quickly, more quickly, or at the same rate as it did when the refrigerator's door was first opened?
Temperature equalization happens exponentially. It starts off with large heat transfer (large temperature changes) and slows down the closer the two temperatures are.
 B.) If the refrigerator is unplugged, what will eventually happen to the flow of heat in the room?
You already said the room was insulated: no heat transfer occurs between the room and the outside world. Thus, the room must stay the same temperature.

- Warren
 P: 59 So, is less, good?
Emeritus
PF Gold
P: 10,427
Questions...Not as much

 Originally posted by Security So, is less, good?
I have no idea what this means.

- Warren
 P: 59 Are less questions more suitable for the forum?
Emeritus