RESEARCH PROJECT : IS IT POSSIBLE TO WALK ON WATER ?

Polystyrene Experiments

 

At first, we had the idea to walk on water thanks to a material which floats, as for example polystyrene.

So we bought a polystyrene panel and we tried several experiments with this material.

Those experiments are based on the archimedes’ principle.

 

      Aim of the experiments:

 

We wanted to find the quantity of polystyrene which would be necessary to allow a person of 75 kilos to walk on water.

 

     First experiment:

 

Protocol:

 

We needed:

• A basin filled with water

• A scale

• Various masses

• Polystyrene

 

First, we cut pieces of polystyrene of various sizes thanks to a cutter.

Then, we chose one and we made it float in the basin of water.

Then, we just added gradually masses until the piece of polystyrene sank and we wrote down the results.

But when we tried to achieve this experiment, we realized that our pieces of polystyrene were not stable on the water. Indeed, when we added some masses, their weight didn’t divide up in a homogeneous way on the polystyrene. So it flipped over, or it sank too early because of our problem of stability.

 

Finally, with this first experiment we realized that it was going to be more difficult to obtain our results because of the lack of stability of the pieces of polystyrene.

 

     Second experiment:

 

Then we decided to do a second experiment and to improve our protocol.

We were inspired by trimarans and their system of floats which stabilizes the boat.

 

 

 

 

 

 

 

 

 

 

 

 

 

http://www.pixelvalley.com/forum/viewtopic.php?pid=240957

http://www.nauticaltrek.com/5610-les-flotteurs-d-un-trimaran-de-loisir

 

So we tried to reproduce these kinds of stabilizers: we cut two small pieces of polystyrene that we fixed on each side thanks to paper clips, and we reproduced the experiment:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Although the stability was better, it was still not enough and the polystyrene sank too early to allow to obtain correct results. Besides, this second experiment was for us the opportunity to realize that there was another problem: by deciding to do our measures thanks to masses, we saw that it was not really precise and that the repartition of the weight on the piece of polystyrene was problematic.

 

     Third experiment:

 

So we built a model which represents a man crawling on all fours on water to avoid the problems encountered before :

To make this construction, we took a bowl, two pieces of wire and four pieces of polystyrene which weighed 45 g each. We used the extremities of one piece of wire to represent two members of the body. We took the bowl to represent the body of a man where we could put in water to model the mass that we wanted to add. We held the pieces of wire and the bowl together by an adhesive tape. The addition of water helps to know the heaviest weight that our construction can bear before sinking.

We put the four pieces of polystyrene at the end of every leg, this represented a man crawling on water with polystyrene as his hands and feet. So we put the construction on water (in a bath) and started to put water in the bowl.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

But at one point the members folded out of the bowl because of the mass of the water which folded the wires. To avoid it, we thought about linking the wires with a thread but it didn’t work.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

So we decided to put the mass under the polystyrene, in the water. The mass must pull the polystyrene downwards . We thought to take a jar to model the mass and we put iron objects (like screws) on it, but when we put this construction on water, we had forgotten that there was air in the jar and thus, it made it float.