2 OBJECTS CAN AFFECT OTHER OBJECTS AT A DISTANCE

Task 3

WORKSHEET Workshop

Materials and tools for a working group:

  • string, thread, wire, rubber band, gauge, scissors, metal hanger, pencil

Task 3 aims at exploring what kind of material the sound spreads better. What pupils find depends on what materials the teacher provides. In the previous task, they found that sound is better propagated by solids than air. In this task, they will explore the various solid materials and determine what properties have solid materials that make the sound better. First, they will introduce them to a situation whereby they will be able to explore the sound distribution through various materials. He shows them how to cut 60 cm long string (all groups start with plain string). A metal hanger (disposable hangers from the dry cleaner) hangs into the center of the string and wrap the ends of the string several times around the index fingers. The pointers are inserted into the ears to ensure good contact with the ear (just enter the ear, no need to insert the ear in the ear). The hangers let loose on the spaghetti in the forward bend. For example, a classmate in a peg hacks a pencil or scissors. The pupil observes how the sound is transmitted by string. He alternately tries to have the string attached to the ears once and not once attached (toes to remove the fingers from the ears). Pupils record the result of the observation in the conclusion of the study, and their teacher guides them to compare the results of this examination with the previous one (Task 2). Subsequently, the teacher will give the pupils different materials (task 3b): thread, elastic band, wire, wool and the like, and asks pupils to try to create preconditions for which of these materials will work to transmit sound similar to string and which better or worse . Part of making predictions is to justify claims, i. the teacher tends to ask pupils what they think is the material they are choosing to behave as they expect.

After making the predictions, the pupils verify them. The teacher points out that they try to create the same conditions for examining all of the materials listed, for example, it is important to use the same piece (always 60 cm) from each material, wrap them around the fingers as well, pound the hanger with the same object and repeat the observation so that research.

If the teacher wants to develop the ability of pupils to propose the process for prediction verification, they will create room for their own suggestions and then discuss the proposals with the pupils, while emphasizing that the pupils correctly grasp the experimental conditions as explained above. After verifying the predictions, the teacher guides the pupils to answer the research question. Reminding them that their job was to find out which material was spreading the sound better. The task of the pupils is to compare the properties of the materials by which the sound is spread well (for example, wire, thread) with the properties of materials that do not spread the sound as well (for example, rubber band, wool).