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Physics : Spring Semester 2023

unit 4 syllabus: waves, sound and music

 

 

Week 7: Feb 14

New assignments this week.

Discussoin: Web-simuation/discussion:The doppler effect.

Plane flying at mach 1: vapor forms at shock front As the pressure wave (sonic boom, "shock wave", etc is dragged by the plane, water molecules momentarily condense in the ultra-high pressure region. As the pressure wave drops (down to partial vacuum and then back up to "normal") the water droplets instantly evaporate back into the "gaseous" state. see the Triple point of water

  
Week 8: Feb 20 Winter Break  

Week 8: Feb 27

(click here to go to last unit syllabus)

New assignments this week.

  • Chpt 11 Questions: 5, 7, 8, 14 +Notes on section 11.2: Energy is an oscillating system.
  • Lab: Simple pendulum (click here to download).

Additional resources:

 

Video/discussion Tacoma Narrows Bridge collapse .. note: this is 1940.. no computer simulation to help them predict this behaviour. Driving force was Vortex shedding.. (great student generated computer model here) (What is Reynolds number?)

  • The function describing the wavelength as a function of the 'mode' of oscillation.
  • The Wave velocity for the first four 'modes' of oscillation.
  • The frequency of the first four modes of oscillation.

Lab: Simple pendulum (click here to download). Good introduction to basic terms and principals of SHM (first for a particle, then for a system)

Physics Girl explains vortex formation in water. Vorteces in fluids are very interesting. Anugular momentum carries the fluid forward.

Tacoma Narrows Bridge collapse .

 

Week 9: March 06

New assignments this week.

  • Text book notes and questions.Chapter 11.2: Energy in a simple, harmonic oscillator. Questions: 5, 7, 8, 14.

Introduction to waves.

Slinky lab: This lab had students using slinkies to generate a set of 'harmonic:" wave forms. Students then measured the wavelength and the period to determine the following:

Discussion of Types of waves.

Polyphonic singing (just her voice) (this clip shows a singer who has leanrned to dampen out the natural overtones of her voice to emphasize individual harmonics, with accomponying frequency analysis graphics to illustrate.

Discussion: Why you can't tune a piano.

 

  

Week 10: March 13

New assignments this week.

Speed of Sound lab. Students first explored tuning forks twisting them around close to their ears, then holding on their skulls and against their teeth. Then we deterimed the speed of sound in air today.

Article: Sound Bytes: Why ears are better than eyes at discerning patterns in data. Students answered questions on this worksheet

Clark was out Tues-Friday

 

Week 11: March 20.

New assignments this week.

Additional resources:

Discussion: the Guitar project descriptor, lab safety, expecatations, etc.

HAML: pop bottle physics! (using bottles filled with water to construct a "pan flute".. of sorts).. Once the bottles were "tuned by ear", students determined the actual frequencies, then compared them to the theoretical frequency progression based on "rules" for the chromatic scale. Discussion: blowing across a soda-bottle: So why does the air vibrate when you blow across it? (recall "vortex Shedding")

  
STOP! The items listed in the weeks below are from Last years syllabus. In some instances, dates may be changed and assigments/activities may be repositioned on the calendar as time progresses.

Week 10: March 07

New assignments this week.

  • article: A crooked, spinning black hole

 

Additional resources:

 

Website/Discussion: Physics of music. This page lays out the actual, mathematical patterns in musical progressions.

 

 

  

Week 18: May 03.

 

Crazy week: Mon/Tues were 'bonding days'.. so no new content..

Video/Discussion: Tesla Coils with Dr. Electric!

 

Week 19: May 10.

New assignments this week.

Build a circuit: Part 1. (see description at right). build a circuit including a battery, two lights, a motor and a switch.

Additional resources

 

This week, we built Snap Circuits kits initially, just learning how to assemble the kits.. and then on Tuesday/Thursday.. building defined circuits and learning how to measure voltage and current using multimeters.

Assignment: Build a circuit: Part 1. build a circuit including a battery, two lights, a motor and a switch. Measure the voltage across each circuit 'element' and the current 'through' the the circuit, under the following two conditions. 1st, with the motor spinning freely.. and 2nd.. when someone physically stops the motor (by grabbing it). Students will note that

 

Week 20: May 17.

New assignments this week.

Monday, Clark went over how to solve circuit problems (given an arrangement of resistors and a known battery voltage, students first determined the 'net resistance' of the circuit, then determined the total current, then determine the voltage drop across each circuit element).

Clark was out mid week, and students worked on assignments at left.

Discussion: How to solve circuit problems when resistors are in PARALLEL.

 

Week 21: May 24.

New assignments this week.

  • Magnetars are amazing!

Additional resources

Discussion: Fundamentals of how electric currents interact with magnetic fields. First step is to understand how magnetic fields differ from electric fields. When we draw the two, what do the 'arrows' represent? Then, to understand that charged particles experience forces in magnetic fields as described by 'the right hand rule' (according to Clark) or the 'left hand rule'. according to Fleming (as described in this video illustrating 'how electric motors work'. which we began watching around the 9 minute mark.

Discussion: Electric motors and electric generators are fundamnetally 'the same' with the only difference being; in a motor, current flowing through the motor turns a wheel to do some work.. and in a generator, somthing 'external' (such as a windmill) turns the crank, which then generates electric current.

Discussion: How to calculate Resistance from measurements of voltage and current (V= IR is Ohm's law) and how to use a multimeter to measure resistance directly (the circuit element must be removed from the circuit to measure and NEVER MEASURE THE RESISTANCE OF A BATTERY!.. it will fry the circuits of the Ohmmeter (as is the case in many of Clark's multimeters).

 

 

  

 

Learning Objective Summary:______

The speed of waves through materials is a function of its mass/density and the spring constant of the intermolecular forces between the adjacent particles/molecules, etc. Wavelength, wave frequency, wave amplititude are all distinctions that we are interested in.

 

  • No new assignments

Additional resources:

For next year: period of pendulum varies with the square root of the length. Original data set show exponential curve, have students plot 8 pts. Assignment has them graph original data set then the root of the data set to see straight line.

Discussion/Introduction to periodic motion. Many (if not all) systems can vibrate (or oscilate). What is interesting however, is that the frequency at which they oscillate is fixed, for a given system. Demo included a mass suspended on the end of a spring. Regardless of how hard I hit it, or where I start it from, the frequency of oscillation didn't change.. the only way to change the frequency, is to change the system.. (i.e., in the spring mass system, to change to a stiffer spring or a lighter mass).

Discussion: Coupled systems discussion and demonstration (two masses hanging from the same support string. Setting one in motion transfers the oscillations to the second). The Desktop coupled system was shown to illustrate a series of coupled (rotational) oscillators.

Clark was out on Thursday, students watched the Sci Fi movie: Moon. Notes for extra credit: How much of this film is plausible?

Playing on Swings really is good for children, and this is why.

The Big Swing at Six Flags Great America (down in Santa Clara?)

 

Week 2: March 02

New assignments this week.

Additional text sections to read (and understand!).

  • 11.1 Simple Harmonic Motion
  • 11.3 The period and sinusoidal nature of SHM

 

 

 

Discussion: Waves propigate through materials based on how how tightly coupled the components (or molecules) are. Restoring forces, coupled systems and basic concepts of modeling materials as series connections of mass on springs was discussed.

 

 

Replica of the Red Baron is built and flown. https://www.youtube.com/watch?v=ArihNioJkGM

Who was the Red Baron?

Discussion: Introduction to shockwaves and the speed of sound. Early aircraft were propeller driven and only flew at several hundred miles per hour. As plane design progressed through the thirties and forties, more powerful engines were used but planes seemd to be magically limited to 500-600 miles per hour (the speed of sound). Without computer simulations or understanding of fluid dynamics, engineers couldn't know that the air flaps wouldn't work at hyper-sonic speeds.

Discussion: History of fast planes. Wright Brothers , tri-planes, P51 mustang.

The first attempts at flight.. flapping wings, spinning gyroscopes, 7 wing planes, etc.

 

 

Week 3: March 09

New assignments this week.

  • Mini-lab: Hallway slinkies.

Additional resources:

Additional sections to read.

  • 11.4. The simple pendulum
  • 11.5 Damped Harmonic motion
  • 11.6 Forced vibrations, resonance
  • 11.7 Wave motion
  • 11.8 Types of waves
  • 11.9 Energy transported by waves
  • 11.11 Reflection
  • 11.12 Interference
  • 11.13 Standing waves, resonance.

Video: Breaking the sound barrier. (history of physics and engineering) (click here for accessory worksheet). (note to Clark..Amazon Prime has a cleaner version)

 

Mini lab: Standing waves on slinkys. (see text at right) Wave 'interference' was introduced, and how waves can pass through each other but the material must conform to both.

Discussion: Types of waves: Transverse, compression (longitudinal) and torsional waves were considered. (as was ocean waves, which involves masses of water tracing out circles). Different waves can propigate through the same material at the same time. Earthquakes were discussed, with differences in P waves and S waves as an example.

For next year: modify string simulator worksheet to include standing waves with an open-end system

 

 

Mini-lab: Hallway slinkies. Students worked in small groups to generate standing waves with their slinkies. The goals were to:

  • To generate standing waves beginning with the fundamental frequency of oscillation (longest wavelength, lowest frequency).
  • To increase the frequency such that the number of nodes increased sequentially (from none in the middle to one to two to three).
  • To measure the period of oscillation for each standing wave pattern and determine the frequency.
  • To determine the wave velocity for each wave.
  • To look for patterns in the frequency and and wavelength.

Discussion: When we draw "sin functions" for wave form such as torsional or compression waves, what does the "Y -axis" represent? (density, displacement, radial displacement for torsional waves, etc.).. Main point was for wave forms other than "transverse or surface" waves, it becomes difficult to "see" the sinusoidal nature of the wave, but we still use sine wave functions to discuss/illustrate etc.

For next year: Have students write slinkylab into standard lab summary format (groups with introduction describing in writing, what the objectives are.. practicing/using terms used to describe wave dynamics)

  • Chpt 11 Question: 8 and Problems: 2, 3, 5, 22.

Week 4: March 16

The first week of 'distance learning'.

This week was a shock to everyone's system.. For many teachers, including Mr. Clark, this week was mainly trying to get our minds around school being closed and the implemenation of 'shelter in place' imposed by the state.

The assignments in physics this week, were the following;

  • to read and take notes on the first three sections of chapter 12.
  • To explore the sound simulation here: https://phet.colorado.edu/sims/html/waves-intro/latest/waves-intro_en.html
  • 1st: Select the LOWER of the two icons in the bottom left, which will allow you to initiate a single pulse. The way to initiate a sound pulse is to ‘push’ the green button. You’ll see a ‘wave form’ propagate across the screen.2nd.
  • Now select the GRAPH function in the upper right corner and repeat the experiment.
  • 3rd: Now select the PARTICLES function in the upper right of corner of the screen and repeat theexperiment.
    • Question: What is being graphed?
  • Now refer to your PHYSICS text book on page 324.
    • Question: What is the displacement of the air molecules (approximately) as this pulse is propagating through the air?
  • Now back to the lower left portion of the screen. Select the ‘continuous wave form’ generating option and ‘push’ the green button again.
    • Describe in words what you observe?
  • Please answer Questions 1-5 in the text book. (page 346).

Due Monday, March 23.

 

 

Week 5: March 23

New assignments this week.

Additional resources:

Monday:

Students should 'click on the Zoom Link' in the class email I will send (in the morning) to install Zoom.. so they can participate in the Zoom Conference call on Tuesday morning.

Students should review sections 12.4 and 12.5 in their text book. Sources of sound; Vibrating Air columns and strings in preparation for Tuesday's Zoom discussion and demo/lab.

Tuesday: Zoom video class/demoStanding waves can occur in columns of air as well as slinkys and bridges. How do we graph these standing wave forms? The same way we graph other wave forms, with sine waves. Click here to see the video recording of the demo and discussion.

Mini-lab:Using tuning-forks and meter-sticks to determine the speed of sound. Clark will demonstrate the lab for the students. The students will record the measurements and attempt to 'determine the speed of sound' from the demonstration. Students will then 'write up' in a one-page lab summary format, the experiment, due next Monday.

Thursday: Students should try and collect several soda bottles. (five is ideal). Clark will demo via Zoom how the lab is organized. Students will follow along and fill out the associated worksheet, Due next Friday.

Soda-pop bottle physics! Creating a major scale by blowing across bottles.

 

 

Click here to see the video recording from Thursday's Pop-bottle physics lab/demo. (note: I'm still having problems uploading this file to the server. it may be too big..I think I can redo it wevideo.. and repost it. if that works, I"ll send an email out to students)

 

 

Week 6: March 30

New assignments this week.

Addit

ional resources:

 

Discussion: Why you can't tune a piano.

Physics of music.

Guitar Project shoulda, woulda, coulda..

The pulse jet powered bike

Music: Marble machine

Quick discussion: accoustic sensors used to identify potential tsunamis also useful for "listening for enemy submarines".. History lesson: The Glomar Explorer used to recover Soviet submarine. Manganese nodules

STOP! The items listed in the weeks below are from Last years syllabus. In some instances, dates may be changed and assigments/activities may be repositioned on the calendar as time progresses.

Week 4: March 18

New assignments this week.

Additional resources:

  • Why you can't tune a piano.
  • 11.1 simple harmonic motion
  • 11.3 the period and sinusoidal nature of SHM
  • 11.7: Wave motion
  • 11.8: Types of waves

Jet Engines, continued:

 

 

Phet Simulation/discussion: Wave intereference in water and sound waves.

Beginning of The Guitar Project!

 

Week 5: March 25

New assignments this week.

  • In-classs reading: Chapter 12.3-.5 Cornell notes due on Friday.
  • The Guitar Project!
  • Article/In Hot Water. This article describes how the vast majority of the excess heat captured by global warming is being absorbed by the oceans, with calamitous effects on ecosystems worldwide.

Additional resources:

 

Clark was out on Monday at a meeting.

In-classs reading: Chapter 12.3-.5 (structure of the ear, sources of sound and quality of sound).

 

The Guitar Project! started this week, students were provided with panels of plywood and 'neck stock'. (Most of the block period was spent in the shop building and cutting parts out).

Introduction to guitar project. "how to build a guitar from standard hardware store parts" was show illustrating how amazing a handmade guitar can sound with less than $10 worth of materials. Tina S. plays van Halen's Eruption

Week 6: April 1:

New assignments this week.

  • Students should be reviewing chapter 16.1 through 16.9. (all about static electricity and charge!). No notes required (to hand in, always a good idea if the goal is to retain knowledge).

 

Additional resources:

 Introduction to electricity and electric fields. What is voltage? Charge? Field strength?

Awesome footage of lightning strikes

Week 4: March 12

Learning Objective Summary:______

This week introduces students to basic music theory including how we ananlyze frequencies, how musical instruments are based on harmonic series and how humans have evolved to appreciate predictable sequences

 

Additional resources:

 

 

 

 

iscussion/review:

Mini-lesson on human evolution: Homo-sapiens evolved a new skill, the ability to control vocal chords to create modern speech. In parallel, we evolved the ability to discern subtle differences in sound to allow us to speak, and along with it, was the ability to play music.

A journey to the most ancient cave paintings in the world.

Week 5: March 27

New Assignments this week:

  • Text book reading/notes (1). chpt 10.8-10.9 fluids

Additional resources:

  • Text book reading/notes (2) chpt 10.10-10.11 fluids

Clark was out o Monday, students used class time to read/take notes on chpt 10.8 and 10.9 on Fluid dynamics. (we have been talking on-again, off-again about fluids, primarily about vortex formation and shedding). These sections lay out basic concepts of laminar flow and Bernoulli's principles.

Discussion/history lesson.developing the first example of "powered flight". the first bi and, the quest for more speed and the "sound barrier".

 

Week 6: April 18

 

Additional resources:

 

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