I'll make a YouTube video with the lecture for today after today's Zoom. If you can't make the Zoom, no worries :). Video is here: https://youtu.be/x19odNth0fc
Zoom Breakout Rooms
Today we'll use something called a breakout room. This is the online version of talking in groups, and we'll use it throughout the rest of the semester. You all already do Think-Pair-Share very well, and this will be our online replacement for that. Some info about using breakout rooms effectively:
You'll be in small groups of 3-5. Please say hi when you arrive in your breakout rooms.
Expectations for professionalism and good netiquette apply in the breakout rooms as well. I'll be floating from room to room, so don't be surprised if I pop in.
Be ready to go from passive to active mode. You've been listening passively, which is fine. Now it's time to engage, talk, and listen.
You will no longer have access to anything in the main room once the breakout session has begun (including the chat and the whiteboard). You will still have access to this website.
Zoom Meeting Agenda 11:00-11:30
1. Welcome
2. Goals
3. Warm-Up
4. Wave interaction demo
We'll watch this during our meeting, but you can preview it if you'd like: https://www.youtube.com/watch?v=kPe1z4GC1uU
Answer the following, to be discussed in break out Zoom groups:
1. What is caused in the water by the up/down movement of the giant tennis balls?
2. When the second tennis ball is introduced, what happens when the two sets of waves interact (collide)?
3. Go to 28 seconds in the video. How many "lines" of relatively calm water do you see?
4. Go to 23 seconds. How are those 6 lines of calm water formed? He's making waves, but in those 6 spots, the waves almost disappear. How is that possible?
5. Each person in your group should be prepared to answer one of the above questions
WARM-UP:
1. If two waves collide with each other, does anything happen? For example, in the bath, at a lake, or at the beach, when two waves interact (collide), does the result of that interaction make a different wave? (Simple yes or no answer)
2. Building on the above question, here are two more specific questions. Remember, peak is the highest part of the wave, and trough is the lowest.
a. If the peak of a wave were to collide with another peak, what would occur? Bigger wave or smaller wave?
b. If the peak of a wave were to collide with a trough, what would occur? Bigger wave or smaller wave?
1. 146A: Wave Interactions, Standing Waves, and Musical Instruments (20 min)
Have you ever strummed a guitar? Plucked a violin? Tapped a piano key? Hope so :). Unless they're electronic instruments, they all have something in common - they're stringed instruments that make sounds via waves. First, build on what we covered in today's lecture on wave interference by learning about standing waves. Then apply that concept to stringed musical instruments
a. Watch, take notes, and answer the edpuzzle questions: Standing Waves Introduction: https://edpuzzle.com/media/5e6cd2a1fc99e7411d552ee7
lecture notes: https://www.flippingphysics.com/uploads/2/1/1/0/21103672/0323_lecture_notes_-_standing_waves_introduction.pdf
b. Watch, take notes: Stringed Instrument Frequencies: https://www.flippingphysics.com/stringed-instruments.html
lecture notes: https://www.flippingphysics.com/uploads/2/1/1/0/21103672/0330_lecture_notes_-_stringed_instrument_frequencies.pdf
2. 146B: Guided Reading: Wave Interactions (20 min)
pay especially close attention to figures 25.11, 25.13, and 25.14, as you'll be using those concepts for an upcoming class.
read all text, answer all questions, fill in all blanks.
Guided Reading: Wave Interactions is on schoology. If you can't access it there, here's a backup LINK
Textbook pg 379-382: LINK
Remind App message me with any questions.
Mr. Alexander
ESSENTIAL QUESTION: How can we prove that EM waves are transverse?
GOALS: swbat...
1. show that EM waves are transverse
2. define opaque and transparent
3. show mastery by scoring 80% or above on quiz
WARM-UP
1. Consider the word, 'void'. What does it mean for a space to be void of matter?
2. A search and rescue worker needs to know the depth of a cave so they can choose the correct length of rope. Which speed should they use to calculate the distance, the speed of Electro-Magnetic waves (aka, speed of light (3x108m/s)) or the speed of sound (340m/s)?
3. If the echo returns to the worker in 1.2 seconds, find the depth of the cave.
CLASSWORK
1. 146A. Quiz
2. 146B: EM waves & Transparent vs. Opaque - Notes & Practice Questions
Opaque: If an object is opaque, then the vibrations of the electrons in the EM wave are not passed from atom to atom through the bulk of the material. Rather the electrons of atoms on the material's surface vibrate for short periods of time and then reemit the energy as a reflected light wave. Such frequencies of light are said to be reflected.
Transparent: Transparent materials are materials that allow one or more of the frequencies of visible light to be transmitted through them
Is water transparent? Are you sure? Think about the photo of the ocean linked here (LINK) ...what color is missing?
Assignment is on schoology in materials. Find it, do it, and submit it there by the end of the period
HOMEWORK
1. Guided Reading: Basic Colors (assigned on Schoology, to be submitted on Schoology). Reading is here (LINK)
Due Sunday 11:59pm
Unable to access today's CW assignment? Here's the LINK to questions
Unable to access today's HW assignment? Here's the LINK to questions