Box with a jumper/blanket on top, cooling or heating?

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Homework Help Overview

The discussion revolves around the thermal dynamics of a box with a jumper or blanket on top, specifically in relation to cooling or heating effects. Participants explore concepts related to heat transfer and insulation in the context of a cooling system using a wet blanket.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants question the role of the jumper in heat transfer, particularly whether it can transfer heat to the contents below. There is also curiosity about the mechanics of a wet blanket cooling system and how evaporation plays a role in temperature regulation.

Discussion Status

The discussion is active, with participants seeking clarification on terminology and concepts. Some have provided insights into the insulating properties of a jumper, while others are still exploring the underlying principles of the cooling mechanisms discussed.

Contextual Notes

There is some confusion regarding the term "jumper," which is clarified as a sweatshirt or jacket. Participants are also navigating assumptions about heat transfer and the effectiveness of insulation in the scenarios presented.

aspodkfpo
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Homework Statement
Kate has a bucket of ice cream and wants to take it on a long car trip into the desert, so she wraps it in a jumper. Is this a good idea? Choose the best answer.
Relevant Equations
nope
Apparently the answer is to have the jumper over the bucket. Am I wrong in thinking that the jumper transfers heat to the ice cream, why does it not do so?

A similar question elsewhere was "Colin claims to have built a refrigerator alternative which works without any power supply. It is a box with a wet blanket over it; the blanket is kept wet as a tap is allowed to drip onto its corner. How does it work?" where apparently it takes energy to evaporate the water on the blanket and thus it keeps is cool. Similarly I thought that warm water would cause the blanket to transfer heat?
 
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what's a jumper?
 
Chestermiller said:
what's a jumper?

a sweatshirt/jacket

can someone please answer? Bump
 
aspodkfpo said:
a sweatshirt/jacket

can someone please answer? Bump
A jumper insulates, i.e. it inhibits transfer of heat in either direction. The heat already present in the jumper soon becomes irrelevant.
 
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