Difference between revisions of "5-WAC-03 Refraction / Reflection"
From MrReid.org Wiki
(→Main Body of Lesson) |
m (→Main Body of Lesson) |
||
Line 15: | Line 15: | ||
* Show pupils the Trigonometry Triangle | * 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.'') | * 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 & | + | * 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== |
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.