Experiences

Date: 2014.11.26

Posted by Uldis (Latvia)

Very good eksperiment,I also did such eksperiment in my class

Date: 2014.10.28

Posted by Maria Dojcanova (Slovakia)

This simple experience engaged my attention and I really like it. I will certainly try it with students in the Physics classroom.
From my experiences - students usually give examples from everyday life by themselves when it comes to the topic "Floating bodies". Objects of different types of materials inserted into the water – they are describing and explaining what is happening. Some of the suggested examples they will experimentally verify during the lesson.
Another experiment when explaining the "floating bodies" – to compare densities of bodies, comparison of operating forces - can be done by using plastic cover of the toys from Kinder chocolate eggs. Experiment:
• empty plastic cover placed in water
• plastic cover filled with salt, sand, etc...placed in water
• gradual removing of the content from the plastic cover
Students are observing and discussing the observed phenomena. The important in those experiments is that pupils may try them at home any time. There is the possibility to discuss the swimming in freshwater lake in the sea (Dead Sea). Illustrative connection of the theory and the practice. Motivation to learn faster and easily; for better and durable awareness of the theoretical knowledge.

Date: 2014.09.30

Posted by Paola Falsini (Italy)

This experience is very interesting!
I promptly tried to replicate it. Its best feature is that the students can do it on their own at home. Indeed, I often try to assign them simple experimental home-works. I think that in this way they can understand that the Physics is not something of abstruse, extraneous or artificial.
Moreover at home each student work individually on the experiment, while at school it is not possible to do it.
However it is still fundamental that, after the initial experiment and observation of the phenomena, a discussion and a workgroup follow in order to lead the students towards the statement of the law/principle.
The value of this experience stays in the fact that the students immediately start thinking about the role of the density of the liquid. Beyond the different sensation of swimming in the sea or in a pool, this experience gives the advantage to change directly (and maybe also to control through measurements) one of the physical magnitudes concerned.
I thought about other experiments to be suggested or that the students could suggest if we motivate them with some questions like “how would you change the experiment?”: we can use other objects (in some cases adding salt is not sufficient to bob up the object); we can add freshwater in order to watch the egg sink again.