Science - Floating and Sinking

We are looking at the properties of items which make them float or sink, and how we can manipulate situations to make something sink that usually floats, or float that usually sinks.



Our first task involved predicting which items would sink or float, and why this might be...


Our second task was using plasticine to show how it could sink and float.  We then tried to make the best vessel to float as many marbles as we could.

This Youtube clip is linked to what we discussed:






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The next experiment we did was about changing the shape of something to make it float.





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Our third experiment was about density.

We made a density column of different liquids in a clear cup and floated different objects in the cup.

 Can you see the different objects 'floating' in the middle of the cup?

The layers occur because the liquids have different densities and therefore the syrup sinks to the bottom while the cooking oil floats on the top.  The water is between the two because it is more dense that the oil, but less dense that the syrup.  The objects float because of density too.







Spangler Science density tower - click here

Science Sparks - click here


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The fourth experiment was to try and make an egg hover in the middle of a glass of water.
Equipment: Cup, egg, salt, water.

Can you make an egg hover?  (No it's not wedged in the cup)



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Our next experiment looked at surface tension and the effects of soap/dishwashing liquid can have.

We put put water in a container then sprinkled pepper on top.  When we put a drop of dishwashing liquid into the water, or dipped a piece of soap into the middlle of the container, the pepper quickly moved to the outside of the container.  This is because of surface tension.  The surface tension was broken by the soap/dishwashing liquid which made the surface of the water pull away.

We then put a cardboard 'boat' into a contain of water and put a drop of dishwashing liquid behind it.  Because the surface tension was broken, the 'boat' moved forwards.

Have a look at the clips below to see what we tried out.






Science Sparks - Surface Tension - click here


Stay tuned to see what else we get up to...