Experiences

Depict of the ball mirrors

Mária Dojčanová

Slovakia

High Secondary School

Physics

Teaching in class

Direct

The aim of the lesson is for the pupils to learn how to actively use the correct terminology from physical geometric imaging - the names of important points, distances, to sketch the image of on object by a spherical mirror and determine the size of the resulting image.
In the motivational phase of the lesson together with the pupils we rehearse what mirrors are, what physical phenomenon they use and what kinds of mirrors we know.
In the exposure phase, I use teaching presentations from digital textbooks so the students perceive the basic concepts through animations. Among them are the optical axis, the paraxial rays, optical center, and radius of curvature, focus, focal length, image size, object size, subject distance and the focal length.
The first projection by the hollow mirror located of the object in front of the center of curvature
(a> r) I draw on the board by myself so I can use all the previous concepts and show the students a way of drawing individual rays. Students at the same time also write notes into their notebooks. It was proved to me to lead the pupils in a way so that when displaying the same type of beam they always use the same color. Then they find it easier to draw additional following views. In the first impressions I always enter all points and all distance signs. On object and image distances I write a note of a signed agreement (a> O, A> O), which pupils then easily get fixed in their heads. The other three locations of the subject pupils just note into their workbooks and leave a blank space. This is their homework to practice a hollow mirror imaging. The fifth location of the object (a r, and