Chapter 5, Section 6
Reflected Light
HW: 5.6 PTG, #1-7, pg. 546, Due Friday
• Learning Objective
– Explain how light rays are
reflected
– Describe the relationship
between angle of incidence
and angle of reflection
• Success Criteria
– Observe the reflection of light
by a mirror
– Identify the normal of a plane
mirror
– Measure angles of incidence
and reflection of a plane mirror
– Collect evidence for the
relationship between the angle
of incidence and the angle of
reflection for a plane mirror
– Observe changes in the
reflections of letters
– Identify patterns in multiple
reflections
• Do Now:
– Copy LO and SC on a
new left side page
– WDYS/WDYT pg. 538
• Agenda:
– Do Now
– Investigate
– Summary
Date:April 16, 2012
HW: 5.6 PTG, #1-7, pg. 546, Due Friday
• Learning Objective
– Explain how light rays are
reflected
– Describe the relationship
between angle of incidence
and angle of reflection
• Success Criteria
– Observe the reflection of light
by a mirror
– Identify the normal of a plane
mirror
– Measure angles of incidence
and reflection of a plane mirror
– Collect evidence for the
relationship between the angle
of incidence and the angle of
reflection for a plane mirror
– Observe changes in the
reflections of letters
– Identify patterns in multiple
reflections
• Do Now:
– Set up notebook for
lab #7-13
• Pg. 540-541
• Sentence starters and
data tables
• Agenda:
– Do Now
– Investigate
– Summary
Investigate
• Read #1-3 (as Class)
• Read rest of investigate and list all
materials for lab
• Check off with teacher
Date:April 16, 2012
HW: 5.6 PTG, #1-7, pg. 546, Due Friday
• Learning Objective
– Explain how light rays are
reflected
– Describe the relationship
between angle of incidence
and angle of reflection
• Success Criteria
– Observe the reflection of light
by a mirror
– Identify the normal of a plane
mirror
– Measure angles of incidence
and reflection of a plane mirror
– Collect evidence for the
relationship between the angle
of incidence and the angle of
reflection for a plane mirror
– Observe changes in the
reflections of letters
– Identify patterns in multiple
reflections
• Do Now:
– Review/Set up
notebook for lab #413
• Pg. 540-541
• Make sure that you
have your Data tables.
• Agenda:
– Do Now
– Investigate
– Summary
Investigate
• Set up notebook for #1-3
• Complete #1-3, OK with teacher
• Set up notebook for #4-6
• Complete #4-6, OK with teacher
• Set up notebook for #7-9
• Complete #7-9, OK with teacher
Investigate
•
•
•
•
Set up notebook for #10-12
Complete 10-12
Clean up area
OK with teacher
Remember-HW DUE FRIDAY!!!
• Learning Objective
– Explain how light rays are
reflected
– Describe the relationship
between angle of incidence
and angle of reflection
• Success Criteria
– Observe the reflection of light
by a mirror
– Identify the normal of a plane
mirror
– Measure angles of incidence
and reflection of a plane mirror
– Collect evidence for the
relationship between the angle
of incidence and the angle of
reflection for a plane mirror
– Observe changes in the
reflections of letters
– Identify patterns in multiple
reflections
• Do Now:
– Explain the
relationship between
the angle of
incidence and angle
of reflection
• Agenda:
– Do Now
– Mazes
– Notes
Your Challenge-Laser Maze Puzzle
• Build a laser maze with your group (15min)
– Create a maze that demonstrates knowledge of
angle of incidence and angle of reflection
•
•
•
•
You may use: Books, a light, notebooks etc.
Maze must fit on your table
Must use 3 mirrors
Must give the group who is going to solve
your puzzle a starting point for the laser
and a “target” for them to hit.
Physics Talk
• What are mirrors
used for?
• To look at your
pretty face!
• Auto safety
• Telescopes
• Cameras
• CD players
• Other technology
• Disco Balls
Physics Talk
• What happens when
a light ray hits a
mirror?
• The angle of
incidence=angle of
reflection
• Ray that strikes the
surface=incident ray
• Ray that is reflects off
the surface=reflected
ray
Physics Talk
• Normal line is
perpendicular to the
mirror
• Angle of incidence is
between the
incident ray and the
normal line
• Angle of reflection is
between the normal
line and the
reflected ray
Physics Talk
• What is the Law of
Reflection?
• Angle of
incidence=angle of
reflection!!!
Physics Talk
• What happens to the • They are reflected off
at the same angle
light rays?
they entered
• If you extend the
reflected rays, where
they intersect is
where the image
appears behind the
mirror
• The distance from
your nose to the
mirror is the same as
the distance from the
mirror to the image in
the mirror
Physics Talk
• Sample problems
• Draw in your
notebook:
– If the angle of
incidence is 40°,
what is the angle of
reflection?
• Also draw where the
image is located
– If the angle of
incidence increases
to 50°, what is the
angle of reflection?
• Also draw where the
image is located
Physics Talk
• Light as waves?
• Light is a wave and
has properties similar
to sound waves
• Light waves are
transverse waves
(motion is
perpendicular to the
direction of the wave)
• Light doesn’t need a
medium to travel
• Also carry energy
(feel warm)
Do Now
• A angle of incidence and a ____________
are ______________.
• If a ray reflects off a mirror with a angle of
30°. The angle of incidence is ______?
• What is the degree of angle for the other
angle on the same side as the angle of
incidence?
Vocab Boxes
•
•
•
•
•
•
Angle of incidence
Angle of reflection
Incident ray
Reflected ray
Normal
Law of reflection
Do Now
• In your notebooks
– Draw a mirror with a “Normal”
– Draw a angle of incidence of 45°.
– Draw and label degrees of the angle of
reflection and other 2 angles.
A person is looking through there rearview
mirror at a license plate on a car that has
WOWO on it. What does the license plate
appear to spell to the driver looking in the
rearview mirror?
• Essential Questions
–
–
–
–
• LO and SC reflection
• Learning Objective
– Explain how light rays are
reflected
– Describe the relationship
between angle of incidence and
angle of reflection
Pg. 545
What does it mean?
How do you know? • Success Criteria
– Observe the reflection of light by
Why should you
a mirror
care?
– Identify the normal of a plane
–
–
–
–
mirror
Measure angles of incidence and
reflection of a plane mirror
Collect evidence for the
relationship between the angle of
incidence and the angle of
reflection for a plane mirror
Observe changes in the
reflections of letters
Identify patterns in multiple
reflections