Burning Up†††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††† Name ____________________________________


The Earthís crust can be moved up and down through faulting and folding.It can also move vertically as the result of the interaction of the downward force of the crust and the upward force of the mantle. The balance between these forces constantly changes as surface processes add material to areas of the crust or take materials away.You can get an idea of how a downward force is balanced by an upward force by doing this activity ad observing how a change in the amount of matter in an object affects the way it floats.



birthday-cake candle††††††††††††††† straight pin††††††††††††††††††† Graduated cylinder†††††††††††††††††† marker

clock †††††††††††††††††††††††††††††††††††††† matches



  1. Carefully and slowly push the pin into the bottom of the candle.CAUTION: Be careful when handling sharp objects. Continue pushing the pin into the center of the candle until the head of the pin is about 2 mm from the bottom of the candle.
  2. Using the maker make a line every cm from the bottom of the candle up.
  3. Fill the graduated cylinder full with water.
  4. Hold the candle by its wick and lower it into the water.Note: Do not let the wick get wet.The candle should float upright in the water.
  5. Record the distance from the bottom of the candle to the water, using the lines you drew on the candle.
  6. Usingthe match, carefully light the candle.CAUTON: Be careful when working with matches and open flames.Extinguish the match by dipping it into running water in the sink.
  7. Every 2 minutes, record the distance from the bottom of the candle to the water.




Amount of candle under water


















Analysis and Conclusions

1.      What happened to the position of the bottom of the candle?

2.      What do you think happened to the weight of the candle?

3.      What relationship do you perceive between an objectís weight and how high it floats?

4.      What does this activity have to do with isostasy?