Thursday, June 16, 2005
Bubble, Bubble Boil and Trouble
Question:
If you are very observant you will notice that a kettle of water will make more and more noise until it reaches a boil then that noise stops, why?
Hints:
The noise you hear are bubbles collapsing. What happens is that the water near the heat heats up some water that goes to a gas (steam) and that little bubble starts rising to the surface. But it quickly encounters some colder water and the bubble collapses noisily.
Once all the water is 100 degrees C then the bubble is more likely to reach the surface and leave that way, which makes less noise.
If you are very observant you will notice that a kettle of water will make more and more noise until it reaches a boil then that noise stops, why?
Hints:
- The noise is made by bubbles
- How is it different before it starts boiling vs. after it's boiling?
- It's different because when it's boiling, all the water has reached 100 degrees centigrade.
The noise you hear are bubbles collapsing. What happens is that the water near the heat heats up some water that goes to a gas (steam) and that little bubble starts rising to the surface. But it quickly encounters some colder water and the bubble collapses noisily.
Once all the water is 100 degrees C then the bubble is more likely to reach the surface and leave that way, which makes less noise.
# posted by Scott Kirkwood @ 10:52 AM 
