Difference between revisions of "5-WAC-03 Refraction / Reflection"
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* Pupils understand that the changing speed of light leads to the pheonmenon of refraction. | * Pupils understand that the changing speed of light leads to the pheonmenon of refraction. | ||
==[[Specifications|Specification]] References== | ==[[Specifications|Specification]] References== | ||
| + | * '''3.14''' recall that light waves are transverse waves which can be reflected, refracted and diffracted | ||
| + | ** Diffraction is SA only | ||
| + | * '''3.17''' describe experiments to investigate the refraction of light, using rectangular blocks, semicircular blocks and triangular prisms | ||
| + | * '''3.18''' recall and use the relationship between refractive index, angle of incidence and angle of refraction | ||
| + | * '''3.19''' describe an experiment to determine the refractive index of glass, using a glass block | ||
| + | * '''3.21''' recall the meaning of critical angle ''c'' | ||
==Starter== | ==Starter== | ||
* Ask pupils to estimate their top speeds on land and in water. | * Ask pupils to estimate their top speeds on land and in water. | ||
** Land: 10m/s (100m runner); water: 2.4m/s (50m swimmer) | ** Land: 10m/s (100m runner); water: 2.4m/s (50m swimmer) | ||
==Main Body of Lesson== | ==Main Body of Lesson== | ||
| + | * Show pupils the Trigonometry Triangle | ||
| + | * Have pupils plot a sine curve on graph paper, from 0 to 360 degrees every 30 degrees. (''Use scale 2cm = 30 degrees.'') | ||
| + | * Talk about the relationship between angle and sine(angle) and about inverse sine by "reading across" from the graph and down to angles. Smarter pupils might note that values "repeat" - that there are two possible angles that give the same sine value - this can be dismissed by pointing out that an angle of more than 90° is less than 90° in the other direction. | ||
| + | |||
==Plenary== | ==Plenary== | ||
==Homework== | ==Homework== | ||
Latest revision as of 13:24, 15 November 2010
Contents
Outcomes
- Pupils understand that light travels at different speeds in different media.
- Pupils understand that the changing speed of light leads to the pheonmenon of refraction.
Specification References
- 3.14 recall that light waves are transverse waves which can be reflected, refracted and diffracted
- Diffraction is SA only
- 3.17 describe experiments to investigate the refraction of light, using rectangular blocks, semicircular blocks and triangular prisms
- 3.18 recall and use the relationship between refractive index, angle of incidence and angle of refraction
- 3.19 describe an experiment to determine the refractive index of glass, using a glass block
- 3.21 recall the meaning of critical angle c
Starter
- Ask pupils to estimate their top speeds on land and in water.
- Land: 10m/s (100m runner); water: 2.4m/s (50m swimmer)
Main Body of Lesson
- Show pupils the Trigonometry Triangle
- Have pupils plot a sine curve on graph paper, from 0 to 360 degrees every 30 degrees. (Use scale 2cm = 30 degrees.)
- Talk about the relationship between angle and sine(angle) and about inverse sine by "reading across" from the graph and down to angles. Smarter pupils might note that values "repeat" - that there are two possible angles that give the same sine value - this can be dismissed by pointing out that an angle of more than 90° is less than 90° in the other direction.
