Bellwork (4/29)
• What is light scattering?
• The deflection of a light ray from a
straight path
Light Scattering
• Why is the sky blue and sunset red?
Rayleigh Scattering
• Polarizes the sky!
Law of Reflection
4/29/14
Law of Reflection
• Law of Reflection: The angle of incidence
equals the angle of reflection
• Incident Ray: the light ray that hits the
surface
• Reflected Ray – the light ray that bounces off
the surface
• Angle of Incidence: the angle between the
incident ray and the line perpendicular
• Angle of Reflection: the angle between the
reflected ray and the line perpendicular
Law of Reflection
Bellwork (4/30)
• What is the Law of Reflection?
• The angle of incidence equals the angle
of reflection
Calendar
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Today (4/30): Law of Refection Assignment
Tomorrow (5/1): Refraction notes
Friday (5/2): Reflection Practicum
Monday (5/5): Pre-Lab
Tues. (5/6): Lab
Sometime: Pop Quiz
Law of Reflection
4/30/14
Law of Reflection
Mathematically:
θ=ϕ
Where,
θ = Angle of Incidence
ϕ = Angle of Reflection
Law of Reflection
• Law of reflection labels:
- “Mirror” [solid line with hash marks “⁄ ⁄ ⁄ ⁄ ⁄”]
- “Perpendicular (normal) line” [dashed]
- Angle of incidence in degrees “θ = x°”
- Angle of reflection in degrees “ϕ = y°”
- Incident ray and reflective ray indicated by a
solid line with arrows (rays can cross)
• NOTE: Line perpendicular, incident ray and
reflected ray have to form a point (vertex)
Assignment: (due Fri 5/2/14)
Design a “mirror maze” that uses at least ten plane
mirrors. You can add a creative theme or
design.
1) Draw the incident ray (rays can intersect)
2) Draw the mirror line with hashes
3) Draw the line perpendicular (90°)
4) Measure the angle of incidence (θ) and include
on drawing
5) Measure the angle of reflection (ϕ) and include
on drawing
6) Draw the reflective ray
7) Repeat until you have a least ten