17.1 How Light Behaves at a BoundaryHow Light Behaves at a Boundary

HowHowlightlight

behavesbehaves atat aa boundaryboundary

By Victoria Skinner

law of reflection law of reflection *If 2 parallel beams strike a mirror 2 reflected

beams are also parallel

*If a line is perpendicular to a mirror it is the normal because it is normal to the surface.

*regular reflection- happens when light is reflected back to the observer in parallel beams *Diffuse reflection- the scattered, fuzzy reflection from a rough surface where light is reflected

reflectionsreflections

Refraction of light

Angle of refraction- the angle the refracted ray makes with the normal to the surface

Angle of Angle of refractionrefraction

Optically denseOptically denseOptically dense- materials with larger indices of refraction with respect to other materials

Snell’s lawSnell’s law• *Snell's law- states that the ratio of sine 

of the angle  of refraction is a constant

Incident Ray traveling in a less dense medium

index of index of refractionrefraction

• *index of refraction- the ratio of the speed of light in a vacuum to its speed in a material*

*The index of refraction often can be measured by directing a ray of light onto the substance's surface, measuring the angle of incidents and angle of refraction,then using Snell’s law..

problem solving strategies-• 1.draw a diagram showing 2 media and label • 2. Draw the incident ray • 3.use protractor • 4.use Snell’s law • 5.use protractor

• 6.evaluate.

*when solving problems involving refractions and reflections of light a one will use a ray diagram .

* when setting up a Snell's law problem assign symbols for the various quantities, and check your results.

Displacement Sensor Topic: Principle of Regular Reflection Measurement. OMRON Corporation , 2011. Web. 28 Feb. 2011. <http://www.omron-ap.co.th/FAQ/ FAQ01367/index.asp>. Dizzo95. "light refraction." 12 Nov. 2009. youtube. Web. 28 Feb. 2011. YouTube<http://www.youtube.com/watch?v=OdcHCRF00jM&NR=1>.

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Unit1_Light.html>.

"Refractometers." Lab Safety Supplies. GHC Specialty Brands,, 2011. Web. 28 Feb. 2011. <http://www.labsafety.com/refinfo/ezfacts/ezf118.htm>.

"Unit 2 Refraction of Light." Creative Commons Attribution Share-Alike 3.0 License. chemicalparadigms, 2011. Web. 28 Feb. 2011. ht

<http://https://chemicalparadigms.wikispaces.com/ Unit+2+Refraction+of+light>.

WORKS CITED

Weblog post. Analysing Refraction of Waves. Nuffnang Web. 28 Feb.2011. <http://fiziknota.blogspot.com/2008/03/ analysing-refraction-of-waves.html>.

Zitzewitz, Paul W, comp. Physics Principles and Problems. 2002 ed. New York: Glencoe, 2002. Print.