17.1 How Light Behaves at a Boundary

behaves at
By Victoria Skinner
17.1 How
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
Refraction of light
Angle of refraction
Angle of refraction- the angle the
refracted ray makes with the normal to
the surface
Optically dense
Optically dense- materials with larger
indices of refraction with respect to other
Snell’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 refraction
• *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.
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