This week, the G10 physics ushered in a new theme: magnetism. Magnetic field is everywhere in our life, the earth is a huge magnetic field, which cannot be seen and touch, unless it is a magnetic material will feel the magnetic force. So in the classroom we need to use special way to make the magnetic field be seen. In physics, they use magnetic field lines to describe the direction of the magnetic field, but these lines are the imaginary lines.
In order to let the students can really understand it, we use iron powder, and compass to visualize the magnetic field lines, as the picture shown. In addition, students understand what is magnetic material and why it is a magnetic material, which is closely related to the chemical structure of the elements. Finally, the classification of magnetic materials is learned, and at this stage,it is divided into two categories: soft magnets and hard magnets, and their specific uses are also discussed.
As an extension, we let students discover many applications of magnetic materials, for example, there are some corresponding magnetic fluid toys on the network can be purchased, what is its mechanism of toys? There are also all kinds of masks in cosmetics, one kind is also made of magnetic fluids, so let the students discuss why these magnetic masks can be used to decontaminate. In addition, there are also household dishwashing liquids that contain magnetic materials, why can they strongly degrease? These are topics of great interest to the students. In addition, at home on weekends, let students make some device, which can also visualize the magnetic field line, it is encouraged to bring the device to school and share it with friends.