平面镜成像英译版.ppt

平面镜成像平面镜成像义务教育教科书义务教育教科书 物理物理 八年级八年级 上册上册Chapter 4:The phenomenon of light Image Formation in Plane Mirrors 一、一、Plane mirrors calm water surface the glass surface the painted floor像像物物二、二、Explorations on the characteristics of image formation in plane mirrors Whats the relationship between the image formedby the plane mirror and the object itself?suppositonsquestion raisingquestion raisingsuppositonexperiment designingequipments: glass plate、 holding device、two torch models which are the same、a piece of white paper 、graduation ruler、pen替代替代火炬火炬 替代平替代平面镜面镜 二、二、Explorations on the characteristics of image formation in plane mirrors 二、二、Explorations on the characteristics of image formation in plane mirrors 1 1、Set the glass plate upright on a horizontal surface and then put the graduation ruler under the glass plate. 2 2、Put one prepared torch model before the glass plate and the other one behind it.3 3、Move the torch model which was put Move the torch model which was put before the glass plate.Get ready for before the glass plate.Get ready for another experiment.another experiment.suppositonexperiment designingquestion raisingexperiment carrying outv Data recording and analysisordinaldistance between the object and the mirror /cmdistance between the formed image and the mirror /cmobject and image size comparisonposition1position2other discoveriesAttention while operating: Set the glass plate upright.二、二、Explorations on the characteristics of image formation in plane mirrorssuppositonexperiment designingquestion raisingexperiment carrying outThe size of the formed image is exactly equal to that of the original subject. Distance from the object to the mirror are exactly the same as that from the formed image to the mirror.The line joining the corresponding points from the formed image and the object itself is perpendicular to the glass plate.Question: What are the deciding factors as for size of the formed image?suppositonexperiment designingquestion raisingexperiment carrying outanalysis and proofExperiment expansion 1、Move the flame direction of the torch model to the right side and try to find its formed image behind the glass plate. 2、Substitute a cardboard for the model behind the glass plate.See if the model can be seen on the cardboard.Position of the formed image and the original object are left and right reversed. Plane mirror imaging comes from the phenomenon of light reflection. For each point of the object (giving out light or glinting), a corresponding virtual point can be found. Usually, dotted line stands for virtual images.三、三、Plane mirror imaging principlessDotted line stands for virtual images.Some Plane mirror imaging characters by experiments: 1、Sizes of the formed image and the original image itself are the same ； 2、Distance between the object and the mirror and that between the formed image and the mirror are exactly the same; 3、The line joining the corresponding points from the formed image and the object itself is perpendicular to the glass plate; 4、Position of the formed image and the original object are left and right reversed; 5、The image reflected is virtual.1Is the moon in the water true? How is it formed?2The distance from the earth to the moon is 3 .8108m，the water depth is 5m，whats the distance from the formed moon image to the water surface?四、四、The application of the plane mirrorimage formation.四、四、The application of the plane mirrorimage formation.四、四、The application of the plane mirrorchanging of the light path.What other places can you find the plane mirrors? ？Plane mirror imagingimaging characters imaging principleThe experiment is thekeyPointer-type clock in the waterLife is just like a mirror, you smile at it, and it smiles at you in return.