Task 1


Materials and tools for a working group:

objects of different weight, worksheet, internet

The teacher initiates a discussion of what is causing the objects to fall. The aim of the discussion is to identify what pupils already know about gravitational force and its effects on objects. The teacher can use the same situation to initiate this discussion as he has used in the object of magnetism - task 1 with sleeping on the table. The teacher guides the pupils to think about which of the proposed ways of shifting the sleeves use the movement of the spine due to gravity gravity. They then consider whether it is possible to move other objects, such as sleep, in the same way. For example, if a book was placed on a paper on a table. The aim is to encourage pupils to realize that it seems that harder objects are not so easy to move, leading to the identification of the first research question aimed at examining whether the rate of falling objects depends on their weight.

First, the teacher asks if they think that the rate of falling objects depends on the weight of the objects. The usual idea of pupils of this age is in the form of Aristotelian perception of the fall rate – the harder the object, the faster it falls. The teacher suggests that they examine this phenomenon. Subsequently, it leads the students to the solution of task 1, where their task is to design a procedure by which they can determine whether the rate of fall of objects depends on the weight of falling objects. He emphasizes this research question, it is best to write it visibly on the board and the predictions that the pupils in the class have made for it.

In terms of the theory of the development of big (complex) scientific ideas, it is important to give proper attention to the procedural side of the research. The research task is of an open type. Such tasks emphasize the researcher‘s competence to propose their own way of verifying predictions. This means that the most important part of pupils‘ active activity is precisely the design of a thoughtful procedure and its discussion. It is advisable for pupils to work in groups, where the teacher walks between groups and advises only if pupils are unable to orient themselves or move on in the task. However, they never advise in a way that would lead them to a particular procedure. In particular, it encourages them to make their own proposals.

When designing procedures, the teacher draws pupil‘s attention to the work with various object characteristics (so-called variables of the examined situation) on which they will test the fall rate. If it is to determine whether the rate of fall of objects depends on their weight, it would be most ideal to have two objects that differ only in weight and the other characteristics (variables; especially shape and volume) have the same.

Recognizing this, there is also a need to address a partial research question to determine whether two objects are equally large. For example, pupils choose to compare the fall rate of two plasticine beads. The larger plasticine ball is even heavier, but it also has a larger volume, it takes up more space, so it would be good to compare the plasticine ball with the same size glass, polystyrene or other ball. However, there is a need to find out if they are actually just as big. Although size comparisons can only be made by estimates, it is more appropriate for them to lead them to the precision typical of scientific procedures and to help them measure whether the balls are the same size (with the same volume), for example by immersing in water in cups (measuring cylinders).

Thinking about this condition is crucial for the success of the idea development. Also, thinking about how pupils will measure (or compare) the rate of falling objects. If the height from which the objects are launched is relatively small (max. 2 meters, if the study is conducted in a school class), any differences may not be sufficiently reflected. Possible differences in this situation cannot even be detected if pupils propose to measure the fall rate using a stopwatch. The differences in this task should not be observed by the pupils (if they do a sufficiently precise investigation), in which case the problem of the untrustworthy results may arise, with the pupils in particular attributing the small amount from which the objects are triggered. For more confidence in pupils, we recommend that you observe, for example, the first floor of a building and compare it, i.e. to ensure a consistent start of the fall of both items from a height and then compare their impact.

The proposed procedures are presented by individual groups. The task of the other groups is to look for errors and untrustworthy parts of the proposed procedures for those groups that present the procedures. The aim of the presentation of the proposed procedures is to modify them so that they are truly usable and truly credible. On the basis of the discussion, they decide how they will verify their prediction and implement the procedure. It is important to observe multiple times so that pupils are sure of the outcome of what they have observed, especially when it comes to research that is likely to disprove their predictions. The results of the observation and the conclusion in the form of an answer to the research task are formulated in the final part of the task by pupils.

In order to the idea to be better anchored, pupils compare their results with the findings they have gained by experimenting with Galileo Galilei. The teacher guides the pupils to find out on the Internet how they have realized their Galileo Galilei experiment. It leads them to compare his experiment progress with the one they did at school. Similarly, they compare their own observation results with those obtained by Galileo Galilei.