What Objects Sink? What Objects Float?

Pre-K have been investigating if an object sinks or if it floats! We were surprised that aluminum foil floats and the shell sinks.

The tin floats if it's empty but sinks if I fill it with water!

Annie, the turtle, can sink AND float!

All the keys sink!

How Solid is Your Tower?

First grade has been learning about properties of solids.  Some solids are flexible or rigid, smooth or rough, opaque or transparent, hard or soft. During this investigation, we were engineers!  As engineers, we needed to know the properties of the solids we were using to build a stable tower.

We measured how tall our tower was.

Sometimes the towers toppled over...so we tried a different way to use our materials to make a stronger tower!

Kindergarten Sinks Wood!

We have been busy learning amazing things about our wood samples!  We discovered that wood floats in an earlier investigation.  Now we are going to try to sink wood!

We were working with two types of wood: pine wood and plywood.  After some trial and error, we attached paperclips to the wood with a rubber band to see what would happen.  

Sometimes the paperclips fall off!

The pine wood needed more paperclips than the plywood
 to make the wood sink.

"I did it!"

Look!  The paperclip is sticking to the wood with no rubber band!

It still isn't sinking!

We came to the conclusion that the pine wood needed more paper clips because it was a lighter wood than the plywood!

The wood can stand right up in the water!

2nd Grade Balances!

Oh the things we can balance! 2nd grade has continued to balance a multitude of objects.  They tried to balance a triangle and an arch in almost a dozen different ways! We discovered that in order for the shape to balance, the counterweight from the clothespins needs to be near or lower than the balancing point!

Next we created our own shapes and made predictions about where the counterweight need to be for the shape to balance!  

Then came the biggest balance of all!  Balancing a pencil on its tip! First we balanced a paper pencil....

...then we tried to balance a real pencil on its tip using only clothespins and wire.    

It took almost the whole period, but eventually we figured it out!

The culminating investigation was creating a mobile that balances!

If you get a chance, stop by the Whitney Museum to see Alexander Calder's mobiles!