Task 6

Materials and tools for a working group:

• box, newspaper, wadding, puffed rice or popcorn, wool or knitted sweater, sand, cellphone (or other sound-generating device)

At the end of the fifth assignment, pupils are concerned at finding out how to stop audio transmission through material. One of the things that pupils usually find is that if we grab the string by hand, the sound in the hand is „lost“, the sound transmission stops, which can be felt in the palm of your hand so that the gentle shake of the palm comes from where the glass speaks and no longer comes out of the other side of the palm.But if we place the palm of the hand gently, we can feel the tremor (sound) passing through the entire palm. In the following task, pupils will focus on exploring what material can be used to dampen the sound best.

First, pupils can try to dampen the alarm or phone by hiding it in a classroom under or behind different materials, but then the teacher leads them to targeted observation by making predictions about specific materials. Pupils solve the task of 6 of the worksheets.

Since it is necessary to observe precisely (for example, we need to use the same amount – thickness, materials) for the actual finding of which of these materials is a better sound insulator, the teacher discusses with the pupils how it will be necessary to implement the procedure to find out which of the materials dampens sounds best. It is important to note that the more material we put on the item, the better the sound is reduced. Therefore, if we want to find out which material dampens the sound, I need to compare the same amount of material. This ensures that the material is placed in the same size container. Even if the teacher suggests a way to do the research, he will make sure that the pupils understand the relationship between how they will observe and what they want to find out by themselves. Emphasize the research question: Which material will silence the best? He then explains to the pupils that they put a cell phone into the box and find out from which distance the sound is no longer heard and mark the distance with the string. He explains the procedure before creating the preconditions for the pupils to know how they will verify their predictions. They can create the prediction by designating an item they think will dampen the sound best (they will only hear it from a very close distance), or the teacher will also determine the ranking, for example, of the first three materials, with the pupils‘ task in writing the material that they think will be best to dampen the sound, two to the one that will also be good, but not as good as the one they put first and so on.

After making the predictions for the individual materials listed in the table to task 6, the pupils fill the box with the indicated material and insert the ringing cell into the material (trying to center it) (the teacher emphasizes that they must always use the same melody and the same volume). Then they will move away from the box and see if the material has muted the sound (only from a smaller distance compared to when the cell was in a box without material) or not. Gradually, they make markings on the floor using a piece of observed object that they place at a distance from which they no longer hear the sound and fasten it to the floor with a piece of adhesive tape. After making all the observations, they will evaluate which material is the one that dampens the best; i the one whose mark is closest to the box, thus evaluating the research question.