======Black vs Silver Can Cooling======


<WRAP right box>
**Materials: **{{$demo.materials_description}}\\
**Difficulty: **{{$demo.difficulty_description}}\\
**Safety: **{{$demo.safety_description}}\\
\\
**Categories:** {{$demo.categories}}
\\


**Alternative titles:** Two-Can Radiation
</WRAP>

====Summary====                   
{{$demo.summary}}



====Procedure====  
  - Boil water in a kettle.  
  - Fill both the black can and the silver can with boiling water.  
  - Cap each can and insert a thermometer (or thermocouple probe) through the cap.  
  - Record the starting temperatures of both cans.  
  - Monitor and record the temperatures at regular intervals as the cans cool.  
  - Compare cooling rates: the black can should cool more quickly due to higher emissivity.



====Links==== 
Black and Silver - Emitting Infrared Radiation - Physics Videos: 
{{youtube>YSl0al1gj_Q?}}\\

📄 Two-can Radiation - buphy.bu.edu: [[https://buphy.bu.edu/~duffy/thermo/4B40_40.html]]\\


====Variations====
  * Try cans of other colors (white, red, blue) to compare their emissivity.  
  * Use painted surfaces versus unpainted metallic surfaces.



====Safety Precautions====
  * Handle boiling water carefully to prevent burns.  
  * Use heat-resistant gloves or tongs when pouring water.  
  * Ensure thermometers or probes are properly secured to avoid spills.




====Questions to Consider====
  * Why does the black can cool faster than the silver can? (Black surfaces have higher emissivity, so they radiate heat more efficiently.)  
  * Why does the silver can retain heat longer? (Shiny surfaces reflect radiation and have lower emissivity, so they emit heat more slowly.)  
  * How does this principle apply to everyday life? (For example, car colors affect heating and cooling, and space blankets use reflective surfaces to retain heat.)  
  * How does this experiment relate to Earth’s climate system? (Surfaces with different emissivity, such as ice versus land, affect how Earth radiates heat into space.)