Task 2

Materials and tools for a working group:

balloon, stopwatch, paper confetti

In the first task, the pupils found that the electrified balloon attracted, for example, paper confetti. In Task 2, pupils will examine whether the amount of paper confetti attracted depends on how long we puff the inflated balloon over the carpet. It is important to use the same sized scraps of paper in this task. To emphasize this (as an element of developing precision in research), it is advisable to guide pupils to produce papers of the same size. Pupils can cut pieces of square paper or use a paper punch. If they use paper confetti, they should first sort them out so that only the same confetti is in the used confetti sample.

Before the actual observation, it is possible to discuss with the pupils their predictions whether the longer rubbing of the balloon by the carpet will create a „stronger“ electrification, which will cause attracting more confetti. During the verification itself, as in Task 1, it is important to carry out a precise survey and use a new balloon for each additional attempt. Pupils dye in the table as many fields as many confetti have been attracted to the balloon, creating a difference diagram. Since the friction time of the balloon in the first column is shown in the order of the shortest to the longest, verification of the possible predictions of proportional relationship between the friction time and the number of drawn confetti can be easily identified in the table („graph“) .

One of the aims of this task is to teach pupils that sometimes it is possible to present the results not in numbers, but graphically, thus highlighting possible differences. When examining some of the balloon‘s confetti, others just „stand up“ - after the balloon approaches, they partially detach from the pad and pull toward the balloon. It is therefore important to agree on what the pupils will consider to be attracted confetti - either only those that remain stuck on the balloon after it has been pulled away from the confetti sample or even those that have been pulled partially. Alternatively, they can be distinguished in color in the table. In this way, we develop a much needed sense of detail and objectivity.