======Hot Air Balloon======


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


**Alternative titles:** Hair Dryer Sky Lantern
</WRAP>

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



====Procedure====  
  - Find a very thin, lightweight plastic bag (such as a dry-cleaner bag or thin trash can liner).  
  - Hold the bag open at the bottom, keeping the opening wide.  
  - Turn on a hair dryer and direct the warm air into the bag, allowing it to inflate.  
  - Once the bag is filled with hot air, release it gently and observe how it rises.  
  - Repeat with different settings (cool, warm, hot) on the hair dryer to compare results.  




====Links==== 
How to Make a Mini Hot Air Balloon | Home Science Experiments - Science Max: 
{{youtube>rrD3RIKXess?}}\\

Make your own hot air balloons - Curiosity Show: 
{{youtube>BG6gL6ehZzs?}}\\

====Variations====
  * Use different sizes and thicknesses of bags to test how mass affects lift. 
  * Use two hair dryers at once to fill the bag more quickly.  
  * Compare how long the bag stays aloft depending on how hot the air is inside.



====Safety Precautions====
  * Keep the hair dryer away from water and avoid overheating.  
  * Do not use sharp or heavy bags that could tear or fall dangerously.  
  * Supervise children to ensure the hair dryer is used safely.  
  * Avoid holding the bag too close to the hair dryer’s heating element to prevent melting.




====Questions to Consider====
  * Why does the plastic bag rise after being filled with hot air? (Because hot air expands, becomes less dense than cooler surrounding air, and creates lift.)  
  * How does the size of the bag affect its ability to fly? (Larger volumes can trap more hot air and stay aloft longer.)  
  * Why does the bag eventually fall back down? (The air inside cools, becomes denser, and can no longer support the bag’s weight.)  
  * How does this compare to using candles as a heat source? (Candles provide continuous heating, while a hair dryer only heats during filling.)