EXERCISE 55 

 WHY DO OBJECTS FLOAT IN WATER? 



Materials. A shallow tin or granite pan ; a galvanized iron pail ; small piece of glass tubing ; 

 paraffin or sealing wax ; beaker ; dry sand ; balance. 



Directions. Punch a small hole in the side of the pail 

 2 or 3 inches from the top. Fit into the hole a piece of 

 glass tubing 2 or 3 inches long, and seal water-tight where 

 the tube passes through the hole in the pail. Fill the pail 

 with water until water flows through the tube. Weigh and 

 record the weight of the pan and beaker. When the water 

 stops flowing, place the beaker under the tube ready to 

 catch water which may flow later. Carefully lower the 



pan, allowing it to rest upon the water in the pail. Weigh and record the weight of the water which 

 now flows into the beaker. Add a weighed quantity of sand and weigh the water which overflows. 

 What is the relation between the weight of a floating object and the weight of the water it displaces ? 



Additional problem. Why will not a cast-iron kettle float ? 

 meant by the " displacement " of a ship ? 



Why does an iron ship float ? W T hat is 



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