Lab 10
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Lab10_phy2_report.docxTA: Keslo Estil SEC#: Name:
Lab 10. Reflection and Refraction
Image formation by reflection and refraction is best understood using a graphical technique called ray tracing. A ray is line that we draw on a diagram indicating the direction in which light is traveling. The nearest physical approximation to a light ray is a narrow beam of light like you get from a laser or, in this lab, from a light source and a narrow slit. When such a beam of light, strikes a boundary separating two transparent media, for example an air-water interface, it is partially reflected and partially refracted. See Fig. 1. In this experiment, the laws governing these processes will be investigated. The law of reflection relates the angles of incidence, a, and reflection, r. The law of refraction relates the angles of incidence, a, and refraction, b to the refractive indices, na and nb.
Objectives
· Investigate the formation of a virtual image by a plane mirror and the law of reflection that governs it.
· Investigate refraction at a boundary and the law of refraction (Snell's Law) that governs it
· Investigate the phenomenon of total internal reflection.
Preliminary Question (1-4)
Analysis (1-6)
Note: Show all equations, calculations and a very clear screenshot of the Excel Spreadsheet to receive full credit, and do not write calculations in the data tables.
Data Tables
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Angle of incidence
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Angle of reflection
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Object distance (cm) |
Image distance (cm) |
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Angle of incidence, |
Angle of refraction, |
sin |
sin |
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· Refractive index of rectangular block:
· Critical angle for semicircular block:
· Refractive index of semicircular block:
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Lab 10. Reflection and Refraction Image formation by reflection and refraction is best understood using a graphical technique called ray tracing. A ray is line that we draw on a diagram indicating the direction in which light is traveling. The nearest physical approximation to a light ray is a narrow beam of light like you get from a laser or, in this lab, from a light source and a narrow slit. When such a beam of light, strikes a boundary separating two transparent media, for example an air-water interface, it is partially reflected and partially refracted. See Fig. 1. In this experiment, the laws governing these processes will be investigated. The law of reflection relates the angles of incidence, a, and reflection, r. The law of refraction relates the angles of incidence, a, and refraction, b to the refractive indices, na and nb. Figure 1 OBJECTIVES Investigate the formation of a virtual image by a plane mirror and the law of reflection that
governs it. Investigate refraction at a boundary and the law of refraction (Snell's Law) that governs it Investigate the phenomenon of total internal reflection.
MATERIALS ray box rectangular transparent prism plane mirror semicircular transparent prism magnetic pins white board PRELIMINARY QUESTIONS 1. When looking obliquely at a window, you may see two reflected images close to each other.
What causes this?
2. Binoculars and periscopes use prisms instead of mirrors to reflect light. How does this happen? Draw a sketch.
3. When hot air rises above a stove top, objects behind it appear to shimmer. What causes this?
4. In Fig.1, which refractive index is greater, na or nb? How would the figure appear if it was the other way round? Draw a sketch.
