Task 7

Materials and tools for a working group:

In the seventh task, pupils observe the same phenomenon as in the sixth task, but while in the sixth task they observed the reflection of light from a mirror in the form of a perceived image of an object in a mirror, in the seventh task they examine how the light itself reflects off the mirror. Task 7a makes the generalizing rule visible, which in some ways perceived pupils in previous tasks. In principle, pupils have to realize that how the light bounces off the mirror depends on how the light falls on the mirror. The more slant it falls on the mirror, the more slant it will be reflected (given that the pupils do not yet dispose with term angle, it is possible to use the simplification that is typical of the expression of this observed phenomenon of primary school pupils).

The teacher suggests to the pupils to better explore how the light is reflected from the mirror. It is advisable to do investigation in a slightly darkened room. It will also help if the pupils‘ space around the worksheet (task 7a) is sheltered by books, for example. For clearer results, it is advisable to use spot light, spotters are suitable as well. It is also important to realize that the path through which light travels is not seen if we do not see it impacting on objects. Therefore, it is good to shine not only on the mirror but also partly on the paper to make it clear where the light travels. It also helps if the edges of the paper on which the lines from the mirror are marked with letters (A, B, C) are set up by the pupils. The reflected light will point to a particular letter, depending on which line we glow towards the mirror.

Pupils in task 7a work directly with a worksheet. They place a mirror perpendicular to the paper on the marked area on the worksheet toward the indicated lines. Then they shine in the direction of the lines 1, 2 and 3 and watch how the light is reflected (in the lines marked A, B and C). Their task is to see how the light is reflected if we point it towards the mirror in line 1, then 2 and finally 3. The results will be recorded in a table in the worksheet and attempted to draw a conclusion. Pupils find out that light reflects still under the same principle. The principle will be examined in task 7b, where their task is to assume first how the light is reflected from the mirror towards the three cards marked with digits from 1 to 3. The aim of the task is not to measure the angles of the pupils. Image can be resolved by approximate determination. They will then try this situation. As in the previous task, it is also advisable to use a light source whose light is not very distracting, preferably a point tactical light or a light pointer.

At first glance, in the second part of the table, the situation is the same, but we do not shine the flashlight on the mirror, but we are looking at it. Again, it is the task of the pupils to make the prediction that they will see all the cards or just some. They then verify their predictions. Verification can also be carried out with the help of one card, which we gradually move and find out when we see it in the mirror and when not. After the examination, the teacher leads the pupils to draw conclusions. The goal was to make the pupils realize that we see objects in the mirror because they reflect the light that then comes into our eyes. In complete darkness, one cannot see anything, but that does not mean that objects cease to exist. Sight uses the presence of light in the environment to identify what is in the environment. Thus, light acts remotely on human eyes, causing objects to be seen. Most objects only reflect light, but many objects light and radiate (for example, sun, stars, bulb, fire, screens, locust flies, and the like).