The Great Water Race

Yesterday, we used wax paper to show how water droplets are cohesive.  The students dropped several beads of water in a small area on a sheet of wax paper.  Next, they gently shook the paper and observed.  The students noticed that the droplets came together to form one large bead.  In some cases, when the small droplets got near one another, they seemed to attract each other like a magnet.  


For the second part of our demonstration, we taped a maze on top of a piece of cardboard and then taped the wax paper on top of the maze.  Students were asked to guide their drop of water from start to finish without going out of bounds.  The students noticed how the water slid on top of the wax paper instead of being absorbed into it.  Almost all the students participated but only six were able to make it through without going out of bounds.

Unfortunately, my camera died before I could get pictures of all the contestants.  Our contestants and their times are as follows: 

Contestant                                     Time

S.W.                                                 34 seconds

A.G.                                                 36 seconds

E.W.                                                45 seconds

J.M.                                                 53 seconds

I.L.                                                   1 minute 3 seconds

M.S.                                                 1 minute 31 seconds

                                                                                          

Tin Foil Boats

In our study of water, the students were charged with the task of creating a vessel that had to meet three standards: 1) be made of tin foil 2) float 3) carry cargo.  The students created vessels of varying shapes and sizes.  Some were rectangular and some were rounded, some were tall and some were shallow.  Next, they took turns floating their boats.  We added pennies one at a time to see how much "cargo" each vessel could hold before sinking.

The results were surprising!  We had three boats that held over 100 pennies!  The owners of these boats were very excited and proud.  They were all good sports, encouraging each other and cheering each other on as the pennies piled up.  Here are some photos from our activity.

100+ Pennies!

We decided that the best floating boats had large surface areas which helped the pennies to be spread out across a larger area.  The walls of the boats were thicker, meaning they were able to push back against the force of the water.  Who knew studying the properties of water could be so fun?

What's up with Water

On our path to learn more about water and the water cycle, we took a side road to talk about properties of water.  We did an activity where we dropped water onto the head of a penny.  In their predictions, students guessed they could fit anywhere between 4-8.  They were very surprised that you can actually fit a lot more than that!  The reason for this is cohesion.  Water tends to stick to itself, meaning the droplets will come together and form one large drop.  Here are some pictures from our demonstration.