THINGS THAT FLOAT
Cartesian Diver
MAKING THE DIVER
Materials: 2 Liter bottle, Water (lots of water) Tank (or sink for testing the floatation), pipet, metal nut, and scissors.
**Link to the kit**
Pipettes- https://www.teachersource.com/product/graduated-transfer-pipets-222/density-divers
Nuts-https://www.teachersource.com/product/cartesian-diver-ballast-nuts/density-divers
Teacher Kits- https://www.teachersource.com/product/cartesian-diversions-class-kit-only/density-divers
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Process:
1.) Take the pipet and slide the nut onto the narrow end, until it is tight and is no longer able to slide off naturally.
2.) Use the scissors and snip off the extra end of the pipet right below where the nut is hitting.
3.) Using the test tank of water fill the pipet to where the bulb has a small air pocket, when released in the tank should float, with only a little portion above the water.
4.) Once the combination of water and air is correct in the diver it is now time to fill up the two liter soda bottle. When filling this bottle up it needs to be completely full, and then the diver should be placed inside the bottle and then toped off with water and sealed tightly.
Below is a video of my professor for further clarification on making the Cartesian divers as well as images of my own bottle as I am creating and testing the diver!
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WHY THIS WORKS
Cartesian Divers work because of the difference of density that is occurring inside of the sealed bottle. When the pressure applied to the bottle changes the density inside of the air pocket in the diver is changing causing the sinking effect.
We begin by holding the bottle with no direct pressure applied, therefore the diver is floating, this is because the air pocket inside the diver is less dense than the water surrounding it.
When we apply more direct pressure by squeezing the bottle we then increase pressure and change the density of the bottle and the air pocket shrinks, making it sink- which then means the density inside of the diver is greater than the water surrounding it because it has now sunk.
When we relate the pressure or our tight squeeze on the bottle the diver will float again because it is now less dense than the water.
In summary things that are less dense FLOAT things that are more dense SINK.
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Fire Works in a Jar
Materials & Preparation
Materials:
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Glass container- Mason jar or Glass cup (I used a cup)
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Liquid food coloring (3 different colors works well; I used red, blue, and green)
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Paper plate for mix oil and food coloring
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Vegetable oil
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Hot/warm water ( I used hot water when preparing because I knew it would cool off before I was ready to use it- then it was warm)
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Fork or other utensil for mixing the food coloring
Process:
1.) Use the container to get hot water fill a little less that 3/4 of the way up. Set aside.
2.) On the paper plate add 3-4 drops of EACH color food coloring that is being used scattered around the plate.
3.) Next pour about 1-2 Tablespoons of oil on the plate over the food coloring, enough that it begins to mix well.
4.) Take the utensil and begin mixing the food coloring with the oil on the plate
5.) Now get the container of what should be warm water and add the mixture of food coloring and oil- OBSERVE! ​
Explanation
What happened when the oil mixture was poured into the water? We notice the drops of oil are floating beads, while the food coloring is slowly dripping out of the suspended oil and through the warm water- creating a firework effect! Why is this happening
-When oil and water meet oil is less dense than water and it will float, the two liquids do not blend because of the difference of densities.
-The mixture of oil and food coloring allows the food coloring to be help in the oil suspension until it becomes more dense and falls through the water- the food coloring will ultimately settle on the bottom of the glass in the drops that flowed through the water.
-However the water is left a tinted shade because of the dispersement of particles as the food coloring traveled through the water- the fireworks!
