1. Wave sketches
Mrs. Hall’s class

2. Sketch 1(top view) Sketch 2 (top view) What I see:
Pulse hits cup; knocks it over
Assume: spring good model of light
What it means:
Pulse has energy; if light is wave, light is energy
What I see:
Wave pulse goes straight, so does reflection
reflection
What it means:
Light travels in straight lines
Sketch 2 (top view)
Nodes form where crest and troughs meet and cancel
WIS:
Steady wiggle rate of hand
1/2λ
WIS:
WIM:
Distance between nodes is 1/2λ
WIM:
I show the full slide first and tell folks to notice the amount of space for each sketch; show landscape style; try to get all class to do this, which helps immensely in grading (faster); at various points along the way, stop and make sure that kids are doing page management as you request.
Do first demo sketch as a worked out example, rather slowly and with lots of help by teacher. Then slowly turn over more responsibility to kids.
Do demonstration first; ask “students” to make sketches and include highlight comments per my prompting; THEN show slides so kids can compare and fill in blanks; motivation: I want them to be successful so I am part of team… not hiding anything from them.
Sketch 1: establish light travels in straight line and is a form of energy
Sketch 2: define what frequency is and how to measure it and represent it in diagram form; establish what wavelength is and how standing wave can be used to “see” it; establish superposition of waves (crest and trough cancel).
Wiggle rate equals frequency

3. Sketch 4: Electromagnetic Spectrum (use λ α 1/f)
WIS:
As wiggle rate increases; distance between nodes decreases
WIM:
λ α 1/f ; in given medium, speed = λ f
Sketch 4: Electromagnetic Spectrum (use λ α 1/f)
Show several wiggle rates but have kids only draw two; help them record the essential difference and the core meaning of what that difference helps us know.
Example problems: show a few worked out calculation problems; tell kids that you are “on their side” regarding getting points and doing well, thus you will show them several calculations that will help them do the test well.
Points: tell them that 50% of grade is are the 3 sketches they just did and 50% is how they did on the two assigned book problems
High energy
High f
Short λ
low energy
low f
long λ
Increasing frequency
decreasing wavelength
Now look at S&T # 5 and R&C #3

4. Ch. 10 Explain: Much Ado About Waves
Light :
is a form of energy
travels in straight lines
acts like a wave
travels at constant speed (in given medium)

5. Ch. 10 Explain: Much Ado About Waves
Let’s add a few details to your sketches:
Amplitude
Crest
Trough
Wavelength
These are on your vocab sheet, too-fill in a definition and draw a sketch on it!!