Science at key stage 3 (Year 8)
Unit 8K: Light
Section 6: How are images formed?
|
|
Objectives |
| Children should learn: |
- that when light is reflected from plane surfaces an image is formed
- to make and test predictions about reflections
- to make and test predictions about the number of images formed in paired mirrors
|
Activities |
|
Outcomes |
|
Children: |
- Introduce the idea of the nature of a 'mirror image' produced in a plane mirror. Ask pupils how such an image differs from the object viewed, and explore their explanations of why this happens,
eg pupils could, in pairs, model object and image in a mirror.
- Ask pupils to explore the symmetry of images by predicting and testing which capital letters or words are symmetrical and by predicting the number of images formed of an object placed between two plane mirrors set at different angles. Encourage pattern seeking so that pupils can make predictions. Show how to 'see yourself as others see you' in two mirrors set at 90° to each other.
|
|
- describe the nature of the image formed in a plane mirror,
eg inverted
- suggest how such an image is formed
- make and test predictions about the number of images formed in mirrors
- record findings, describing patterns in these
|
|
Points to note |
- Although the mirror image appears to be laterally inverted, this presents the problem of why it is not inverted top to bottom as well. It would be more accurate to say the mirror inverts 'back to front'. This can be demonstrated by writing on an overhead transparency (OHT), holding it in front of a mirror and looking through it at its reflection.
- The relationship of the angle between the mirrors (A) to the number of images (N) is expressed as A(N+1) = 360. It is helpful to suggest that pupils initially investigate angles that are factors of 360.
|
|
|
This unit is divided into sections. Each section contains a sequence of
activities with related objectives and outcomes. You can view this unit by
moving through the sections or print/download the whole unit.
|
|
|
