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Czech originalMultiple Question Experimental Set-Ups
The idea of set-ups accompanied by many questions presented in this contribution can be very useful for the tuition of physics. The usage of these set-ups in repetition focused classesmakes learning more interesting for the students, facilitates the understanding and retention of newly acquired knowledge. The idea was purely practical in its inception. For many years, when organizing the finale of the secondary school physics tournament, these practical experiments became a sort of tradition in our region. These experiments, prepared just for the tournament, got the name “Multiple question experimental set-ups”. The idea behind these sets is that it was possible to form many questions on the topic of demonstrated phenomena or processes. The experiments in each set-up are either about the phenomenon itself and show its different manifestations, or about several different phenomena manifested to the outside world in a similar way. Especially the latter set-ups can fulfil a very inspiring role in tuition by the way they show natural processes.
To illustrate the aforementioned ideas, we chose two examples of “Multiple question experimental set-ups”. We will present them in the way they are shown at the physics tournament, where the number of questions is limited to four. The description of the experiments is very brief as well, so that the essence of the experiment doesn’t show itself until the very last second. It is up to the contestants to fully answer all the questions related to the observed experiment. When using the “Multiple question experimental set-ups” shown below for tuition purposes, it is possible to formulate the questions differently, list more of them, or modify the set-up itself. It is important, however, to realize that a large number of questions, or questions that are very detailed can worsen the didactical effect; the number of questions listed herein seems optimal.
Set-up I
1. Two translucent boards are placed between a light-bulb and a shade.
We turn board 1 and observe periodical changes of light intensity on the shade.
Question 1 (explanation):
How do you explain this phenomenon?
2. One polarizer is removed, but light points to a glass board placed in a Hartl optical disc
Question 2 (prediction):
Will the intensity of light change while turning the polarizer?
3. The polarizer is removed from the previous set-up. While turning the board, we observe changes in light intensity of light reflected from the glass.
Question 3 (explanation):
Why does the light intensity change?
4. The set-up is the same as in example 1. The two polarizers are placed so that the shade is not illuminated. Then we place another polarizer (3) between the polarizers (1) and (2).
Question 4 (prediction):
Will the picture on the shade change? Explain your answer.
Question 5 (prediction):
What will the swapping of polarizer (2) and (3) cause?
Set-up II
Three identical carts are connected with dynamometers (see below). We pull the whole set with the force F.
Question 1 (prediction):
What will the relation between the values measured on dynamometers S1, S2, S3 be?
2. The same set of carts (from point 1) are placed on an inclined plane (see below)
The force F keeps the framework balanced.
Question 2 (prediction):
What will the relation between the values measured on dynamometers S1, S2, S3 be in this case?
3. A line connected to two walls using two identical dynamometers (S1 and S3) is pulled around two pulleys (see below). In the middle of the line another dynamometer (S2) is placed.
We pull the dynamometer S2 with a force that shows 50 units.
Question 3 (prediction):
How many units will be shown on S1 and S2?
4. The experimental set-up is similar to the one in point 3. We pull on the dynamometer S2 in the middle of the line (see below).
Question 4 (prediction):
What will the relation between the values measured on dynamometers S1, S2, S3 be?
The results of many of these experimental set-ups are surprising, which only heightens their attractiveness, it arouses the students’ interest and provokes their questions. Stimulating such a state in students is an extremely important thing, because this, in turn, leads to the success in the teaching of physics.