From the Classroom to Outer Space
II. The FUSE Satellite
Activity #4
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Exploring Our Universe:
From the Classroom to Outer Space II. The FUSE Satellite Activity #4 |
TRACING LIGHT THROUGH:UNDERSTANDING DIFFRACTION
Notes to the Teacher
| Level/Course: | Grades 9 and up. Physics |
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| Time Required: | One class period or more if optional activities are included. |
| Objectives: | Students will:
Demonstrate understanding of reflection and diffraction by sketching the path of star light through a simple model of the FUSE science instrument. Derive and the grating equation and use it to solve a problem. |
| Prerequisites: | Particle and wave models of light, characteristics of waves (wavelength, amplitude, interference), Law of Reflection, triangle trigonometry. |
| Materials: | Student activity sheet, protractor, scientific calculator. |
| Optional Demonstration Materials: | Hand held diffraction gratings or spectroscopes, ripple tanks or baking trays. |
| Procedures: | 1. If diffraction gratings or spectroscopes are available allow
students to observe spectra, then explain that they are seeing a phenomena
that is explained by viewing light as a wave. If time allows, do Activity
#6 in Kit 1 of this series.
2. After students have read the first two sections of the activity sheet entertain questions. 3. (Optional) Have student groups do the water wave activity. 4. Students work in groups on "TRACING LIGHT THROUGH FUSE." 5. Ask students to summarize results and ask for other examples of diffraction 6. (Optional) Do Activity #7 in Kit 1 of this series. |
| Discussion: | This activity emphasizes a poorly understood difference between the two models used to describe light: wave and particle. The mathematics used to derive the grating equation is simple but the physics is difficult because the derivation requires understanding many abstract concepts about wave phenomena. The ray tracings in the activity give students a concrete representation of these abstract ideas. |