On the Faculty of Math and Physics, of University in Ljubljana, we the freshmen of physics visit a course called Lab works lead by doc. dr. Gorazd Planinšič. Each student is assigned into a group, and each group gets an assignment. Our group got this task:

"Measure the fundamental eigenfrequency of a rubber balloon. In your group think of different ideas how to conduct the measurements. Using your method measure the fundamental eigenfrequency of an air-filled and helium-filled balloon of the same size. In both cases determine the pressure in the balloon. Try to predict the ratio fundamental frequencies. Also try to measure some higher eigenfrequencies."

The site you are reading was written as a report to prof. Planinsic who probably wants our work to be helpful to other people (and not that the only results of it would be a piece of paper in his drawer and a mark in our indices) and therefor he demands the report to be in web-able form. The requested form of the report also had some educational side effects and we are all nothing but grateful for that.

The leader of the project was Samo Lasic who also helped us with practical work and theoretical background. Ales Kete helped us with immortilazing our images for further generations by means of digital photography. And at last Borut Levart taught us basics of HTML - the web-able report.