Quinones 1
Layla Quinones
CPA 011.3872
April 27, 2009
Learning Journal #3
Class Lesson “Script”:
(The teacher enters the classroom and writes the aim on the white board).
Aim: What is light?
(The instructor poses a situation to the students along with a question).
Instructor: Pretend you are descending into a dark cave. You are walking further into
the cave and you realize that you have walked far enough that you see nothing at all, not
even your hand in front of your face. Why is it that you cannot see anything when you are
this far into the cave?
(The instructor takes answers from the students and tries to lead them into the direction of
the right answer).
Answer: You cannot see anything because there is no light in the cave to bounce off of
objects therefore, your eye cannot pick up any images.
Instructor: Why?
(The instructor takes answers from the students and tries to lead them into the direction of
the right answer).
Answer: Light reflects off of the objects you are looking at.
(The instructor begins to start the lesson with a basic element of seeing as pertaining to
light)
Instructor: Light is exerted from the sun and other light sources, then the light waves
bounce off of objects that are present making them visible to the viewer.
(Writes definition on the board).
Def: Light is a electromagnetic disturbance that can produce the sensation of sight.
Instructor: We know that: v= F(lambda)
So if we derive a new equation using the last one replacing v with c then: c= F (lambda).
C is considered the speed of light which is on your reference tables, Look at your
reference tables and give me what the speed of light is equivalent to.
(Writes on the board after calling on students for the answer).
Speed of light: c=3.00x10^8 m/s
Instructor: So now that we know that vision is a result of light reflection off of objects,
what is reflection?
(The instructor takes answers from the students and tries to lead them into the direction of
the right answer. She writes the correct answer on the board).
Def: Reflection is the rebounding of waves on the surface of a new medium or barrier.
Quinones 2
(The instructor then begins to draw a visual graph on how reflection is represented. She
uses the regents test content to show this).
Consider:
Instructor: How would you describe the incident angle?
(Takes answers from students)
Answer: The incident angle is formed by the incident ray and the normal.
Instructor: How would you describe the angle of reflection?
(Takes answers from students)
Answer: It is formed by the reflected ray and the normal.
(Writes on the board)
RULE: the angle of incidents is equivalent to the angle of reflection.
(Gives an example problem on the board)
Question: What is the angle of incidents? What is the angle of reflection?
(Takes answers and explanations from the students)
(Writes on the board)
- The Law of reflection states that the angle of incidence is equal to t he angle of
reflection (Thea i = Thea r) and that the incident ray, normal and reflected ray all
lie in the same plane.
Instructor: Why when you look in the mirror there is a reflection but on other surfaces
there is not?
(Takes answers from students)
Instructor: Why when you add polish on a dull surface you can all of a sudden see
reflected light?
(Takes answers from students)
(On the board)
-Here the waves are parallel when they come in and reflect out.
Quinones 3
Here the waves come in parallel but cannot leave parallel because the surface is not
straight or smooth enough. It can not recreate an image in your eye due to the uneven
surface therefore, making the light bounce off unevenly.
Def: Regular reflection is produced when light rays are incident upon a smooth plane
surface.
Def: Diffuse reflection is the scattering of light caused by reflection from an irregular
surface.
(The bell rings and the students pack their books and exit the room from front and back
doors).