Do the experiment and note down your observations and findings

Changing Buoyancy

What I need:  
Some clay balls, A glass, A bottle of soda  
What I do:  
Pour a soda into the glass. Then quickly put a tiny ball of clay into it.  
What I observe:  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -.
The question that occurs to me: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - --.

   Here is an analysis:  

  • Why did the ball of clay sink ?  
    (Tick the right answer)
     It was heavier than the buoyant force 
    It was lighter than the buoyant force  
          What is buoyant force?
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  • What brought the ball of clay up to the surface ?  
    ( Tick the right answer)
     The bubbles in the soda  
    Some of the clay breaks off in the water and makes the ball lighter

  • Why does the clay ball sink again then?  
    ( Tick the right answer)
     The clay ball becomes heavier with so many bubbles
    The carbon-di-oxide is released into the air when the clay ball comes to 
         the surface 

  • Why does the rising and the sinking last for only a short time ? 
    ( Tick the right answer)
     Most of  the carbon-di-oxide in the glass is released into the air  
    The clay ball gets heavier and heavier with time

  • Do you think the effect of rising and falling will last longer if the glass is kept partially closed?
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