Difference between revisions of "5-WAC-02 Reflection / Using a Raybox"
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* Pupils understand the law of reflection. | * Pupils understand the law of reflection. | ||
==[[Specifications|Specification]] References== | ==[[Specifications|Specification]] References== | ||
| − | ==Starter== | + | * '''3.14''' recall that light waves are transverse waves which can be reflected, refracted and diffracted |
| + | * '''3.15''' recall that the angle of incidence equals the angle of reflection | ||
| + | ==Starter== | ||
| + | * Pupils to write down the names of all the parts of the raybox that they can remember. Check what they remembered: | ||
| + | ** Power supply | ||
| + | ** Bulb | ||
| + | ** Lens | ||
| + | ** Slit(s) | ||
| + | ** White paper (this now counts as part of a raybox) | ||
==Main Body of Lesson== | ==Main Body of Lesson== | ||
| + | * Explain to pupils that when light strikes a surface, three things (or a combination thereof) can happen: | ||
| + | ** Absorption (e.g. blue light on a red surface) | ||
| + | ** Transmission (e.g. light through glass) | ||
| + | ** Reflection (e.g. image formation by a mirror) | ||
| + | * Be careful to note that there is usually a combination of processes: light hitting glass is not 100% transmitted - a small portion is reflected. | ||
| + | * There is a good opportunity here to talk about "one-way mirrors" and to demonstrate the effect of light levels on reflection with Pepper's Ghost. Another good example is train carriages: during the day you see out, during the night you see a reflection of the carriage's interior. | ||
| + | * Question pupils on what the "rules" governing reflection are likely to be. One will doubtlessly get the idea of angle of incidence = angle of reflection, but not in those words. | ||
| + | * Give pupils the "official" form of the law of reflection (whatever that may be). | ||
| + | * Revise how to use a raybox. Remind pupils to tape down an A3 sheet of paper before starting. | ||
| + | * Revise how to draw the normal to a surface. | ||
| + | * Pupils use raybox and small mirror to create three lines of incidence and three lines of reflection (in different colours). | ||
| + | * Demonstrate how to measure angle using a protractor. Yes, I'm serious. A lot of them really don't know how to use a protractor effectively. They have a vague idea, but aren't sure. Use WRK181 to check ability to measure angles. | ||
| + | * Emphasise the necessity of measuring between ray of light and normal. Angles are never measured between surface and ray. Use WRK182 to practice measuring angle of incidence/reflection. | ||
| + | * Demonstrate how virtual images are formed by reflected rays of light. | ||
==Plenary== | ==Plenary== | ||
==Homework== | ==Homework== | ||
| Line 11: | Line 33: | ||
=Additional Information= | =Additional Information= | ||
===Resources Required=== | ===Resources Required=== | ||
| + | * Pepper's Ghost | ||
| + | * A3 paper | ||
| + | * Rayboxes | ||
| + | * Small mirrors | ||
| + | * Protractors | ||
===Textbook References=== | ===Textbook References=== | ||
===Website References=== | ===Website References=== | ||
| + | * Gorillaz and Madonna used Pepper's Ghost at the Grammy's a few years ago: [http://www.youtube.com/watch?v=6_gnMOom7kE http://www.youtube.com/watch?v=6_gnMOom7kE]. | ||
===Skills Addressed=== | ===Skills Addressed=== | ||
===Safety/Hazards=== | ===Safety/Hazards=== | ||
===Notes=== | ===Notes=== | ||
Latest revision as of 12:34, 26 October 2010
Contents
Outcomes
- Pupils can use a raybox.
- Pupils can define the term 'reflection'.
- Pupils understand the law of reflection.
Specification References
- 3.14 recall that light waves are transverse waves which can be reflected, refracted and diffracted
- 3.15 recall that the angle of incidence equals the angle of reflection
Starter
- Pupils to write down the names of all the parts of the raybox that they can remember. Check what they remembered:
- Power supply
- Bulb
- Lens
- Slit(s)
- White paper (this now counts as part of a raybox)
Main Body of Lesson
- Explain to pupils that when light strikes a surface, three things (or a combination thereof) can happen:
- Absorption (e.g. blue light on a red surface)
- Transmission (e.g. light through glass)
- Reflection (e.g. image formation by a mirror)
- Be careful to note that there is usually a combination of processes: light hitting glass is not 100% transmitted - a small portion is reflected.
- There is a good opportunity here to talk about "one-way mirrors" and to demonstrate the effect of light levels on reflection with Pepper's Ghost. Another good example is train carriages: during the day you see out, during the night you see a reflection of the carriage's interior.
- Question pupils on what the "rules" governing reflection are likely to be. One will doubtlessly get the idea of angle of incidence = angle of reflection, but not in those words.
- Give pupils the "official" form of the law of reflection (whatever that may be).
- Revise how to use a raybox. Remind pupils to tape down an A3 sheet of paper before starting.
- Revise how to draw the normal to a surface.
- Pupils use raybox and small mirror to create three lines of incidence and three lines of reflection (in different colours).
- Demonstrate how to measure angle using a protractor. Yes, I'm serious. A lot of them really don't know how to use a protractor effectively. They have a vague idea, but aren't sure. Use WRK181 to check ability to measure angles.
- Emphasise the necessity of measuring between ray of light and normal. Angles are never measured between surface and ray. Use WRK182 to practice measuring angle of incidence/reflection.
- Demonstrate how virtual images are formed by reflected rays of light.
Plenary
Homework
Additional Information
Resources Required
- Pepper's Ghost
- A3 paper
- Rayboxes
- Small mirrors
- Protractors
Textbook References
Website References
- Gorillaz and Madonna used Pepper's Ghost at the Grammy's a few years ago: http://www.youtube.com/watch?v=6_gnMOom7kE.
