Class 32: Monday, 5/11/26

Warm-up:  

The diagram on the right shows top views of the same boy looking into mirrors.  On the right, the mirror is a simple flat mirror.  On the left, the mirror is two separate mirrors arranged at right angles.  The boy has one blue eye and one green eye.

When he looks in the mirrors, where will his blue eye appear to be?  Why?

 

Today:

Until Next Class: None
Class 31: Thursday, 5/7/26

Warm-up:  

ppt

Today:

Until Next Class: None
Class 30: Tuesday, 5/6/26

Warm-up:  Suppose you have a shirt that says "shirt" on the front.  When you look at your shirt in a mirror, which of these do you see?  Why don't you see the other one?  In other words, why do mirrors seem to "flip" images one way, but not the other?  What's going on? Here's a hint...

Today:

  • Finish the project -- except for the music videos -- In Google Classroom
  • Collect data for everything except the music videos.  Instead of recording sounds, record videos with sound using your Chromebook.  That way you can put the videos right into your drive and slideshow.
  • Next class: begin the final unit (Optics), finish your music videos, and submit your slideshows.
  • Optics Handout1 (PDF)   Filled in notes

Until Next Class: None
Class 29: Friday, 5/1/26

Warm-up:  

1. What does "play harmonics" mean? 

2.  How is playing harmonics different on a string instrument vs a wind instrument?

  • Harmonics played on a violin (video)

  • Harmonics played on a flute (video)

  • "Taps" played by the US Marine Band -- watch at 2X

  • "Taps" played by a guy swingin a flexible pipe

    • Today:

    Until Next Class: None
    Class 28: Wednesday, 4/29/26

    Warm-up:  

    1. How does a bow cause a string to vibrate at its resonant frequency?
    2. Why does it help to wet your finger when you make sound by rubbing the rim of a wine glass?

     

    Today:

    1. Check the steps from last class.  Focus on these to finish the guitars...
      1. Add the nut and fine-tune
    2. Begin Project -- In Google Classroom

    Until Next Class: None
    Class 27: Monday, 4/27/26

    Warm-up:   Pickups, Amps, and Speakers

    The permanent magnet of the pickup on the right magnetizes the nearby section of steel string, causing the string to become a magnet that is attracted to the pickup magnet. 

     

    1.  What is the direction of the string's magnetic field -- which side of the string is North, and which is South?

    2.  If the wire is moving upward, is the pickup coil experiencing a strengthening or weakening of that magnetic field?

    3.  Electric current begins to flow through the coil, so that the coil produces a magnetic field to counteract the change in its field caused by the moving string. 

    4.  Is current flowing toward the pickup through wire segment A or through B?

    5. Assuming that current travels straight through the amplifier on its way to the speaker, is the speaker cone currently being pulled toward the speaker magnet, or is it being pushed away from the speaker magnet?

     

    Today:

    1. Check the steps from last class.  Focus on these to finish the guitars...
      1. Measure your scale length and use your fret calculator to mark the frets
      2. Install your frets by wrapping the fishing line.
      3. Add the nut and fine-tune
    2. Begin Project -- In Google Classroom

    Until Next Class: None
    Class 26: Thursday, 4/16/26

    Warm-up:   Can you identify any nodes or antinodes in this backyard pool?

     

    Today:

    1. Next steps:
      1. Fine neck sanding?  But not on finger board.
      2. Finish plugs -- solder plug to wire and alligator clips.
      3. Small, side screws in the front of the peg box.
      4. Install the peg box restraining bar.
      5. Screw-in wire pegs
      6. Insert tuning anchors
      7. Attach strings
      8. Insert and position pickups -- temporary position -- try the instrument
      9. Mark fret positions.
      10. Wind frets

    Until Next Class: Have a great break!
    Class 26: Tuesday, 4/14/26

    Warm-up:  

    Does the Airzooka send a wave through the air?  How can we tell if it's a wave?

    vortex cannon

     

    Today:

    1. Finish Notes:  Music Notes and Fret Spacing and  (PDF)
    2. Make Fret Calculator Spreadsheets:
    3. Cut necks.  I will take them home to sand.
    4. Make plugs -- solder plug to wire and alligator clips
    5. Finish pickups and test with mini-amps

    Until Next Class: None
    Class 25: Friday, 4/10/26

    Warm-up:  

    I am going to submerge an open pvc pipe in water.  Then I will pull the pipe vertically out of the water, holding a ringing tuning fork next to it.  At some point(s) the sound of the tuning fork will get louder and then quieter again. 

    1.  Why will the sound get louder?

    2.  If we measure the pipe height at which the sound gets loud, we can calculate the speed of sound.  How?

     

    Today:

    1. More Notes:  Music Notes and Fret Spacing and  (PDF)
    2. Make Fret Calculator Spreadsheets:
    3. Decide on your scale length (saddle-to-nut) distance
    4. Attach "peg box" and bridge.
    5. Draw lines to cut neck and pickup slot -- and cut?
    6. Make plugs -- solder plug to wire and alligator clips
    7. Finish pickups and test with mini-amps

    Until Next Class: None
    Class 24: Wednesday, 4/8/26

    Warm-up:   What is a Ruben's Tube?  How does it work?  What can you do with it?

     

    Today:

    Until Next Class: None
    Class 23: Monday, 4/6/26

    Warm-up:  

    What evidence suggests that resonance did (or did not) cause the tacoma narrows bridge to collapse?  Link 1  Link 2

     

    Today:

    Until Next Class: None
    Class 22: Thursday, 4/2/26

    Warm-up:  

    1.  What do the terms resonance and forced vibration mean?

    2.  Which term applies to the body of a string instrument amplifying the string's sounds?

    3.  Which term applies to breaking glass with sound waves? 

    Today:

    Until Next Class: None
    Class 21: Tuesday, 3/31/26

    Warm-up:   What is going on in this video?  Why does the salt pile up in specific locations?

    Today:

    Until Next Class:  Prepare for test over sound and waves
    Class 20: Friday, 3/27/26

    Warm-up:   Is this a real photo of a string?

    Today:

    Until Next Class: Quiz 2 next class
    Class 19: Wednesday, 3/25/26

    Warm-up:  

    1.  What's happening in the "Amazing Water and Sound Experiment?"

    2.  How can we reproduce this with a fan and a variable speed strobe light?

    Today:

    Until Next Class: Quiz next class
    Class 18: Monday, 3/23/26

    Warm-up:  

     What is a wave?  What is a sound?  How do ears work?

    Khan Academy Sound Waves 

     

    Today:

    Until Next Class: none  

    Class 17: Tuesday, 3/17/26

    Warm Up:    

    1.  Is there anything wrong with the diagram on the right?

    2.  Why is the north pole of a magnet called the "north" pole?

    Today: 

    Until Next Class:  Quiz next class.  Do the  Quizlet Google Classroom assignment.
    Class 16: Friday, 3/13/26

    Warm Up:    We have three identical corded drills and two drill bits.  We need to drill something in a location that is farther from an outlet than the length of the cord of a drill.  How can we do this without using other materials or disassembling a drill?

    Today: 

    • Wrap up the magnetism projects.
    • Fix speakers -- try to drive them with the classroom receiver
    • Try to turn the motor coils into generator coils -- light an LED and measure voltage??

    Until Next Class:  None
    Class 15: Wednesday, 3/11/26

    Warm Up:    How does this speaker work?

    Today: 

    • Finish buzzer and motor assignments
    • Make a speaker using 2m of 28gauge enameled wire, a large magnet (we will share), an audio jack with alligator clips, and paper.   You will also need glue and/or tape.  Here's what mine looked like before I snipped off too much of the air pushing surface ("cone") .  Here are the directions. 

    Until Next Class:  None
    Class 14: Monday, 3/9/26

    Warm Up:    How does this electric motor work?  How can it be improved?

    Today: 

    • Return/review circuit tests
    • Troubleshoot the troublesome buzzer.  Finish buzzer videos.
    • Disassemble buzzers and return parts.
    • Make a motor and a video explaining how it works -- see Google Classroom.

    Until Next Class:  None
    Class 13: Thursday, 3/5/26

    Warm Up:    Can you guess how this buzzer buzzes?

    Today: 

    • Return/review circuit tests
    • Absent students take circuit tests
    • Make a solenoid buzzer:  Watch this instructional video showing how to make a Solenoid Buzzer.  Draw a sketch of a solenoid buzzer design that uses only the materials below:
      •  wood, nails, hot glue/glue guns, drill/drill bits, screws, enameled wire (10m of 28 gauge), sandpaper (and belt sander), saw (not really necessary), strips of springy magnetizable steel (approx 0.5" wide, 3" long), and a D.C. power source (set betwen 3V and 6V). 
      • With those materials, you will have to make a working solenoid buzzer, as shown in the video.
    • Make a video.  In the video, show your buzzer working and explain how it works.  Everyone in your group (who wants credit) must explain part of this.  See Google Classroom for details, and to turn in the the video.

    Until Next Class:  None
    Class 12: Friday, 2/20/26

    Warm Up:    What is a solenoid?  How does it work?

    Today: 

    • Quiz over Circuits
    • Episode 1: Sources of Electricity (start at 4:10; stop with solar)
    • Next Activity:  and test the solenoid for this project...
      • Make a solenoid buzzer:  Watch this instructional video showing how to make a Solenoid Buzzer.  Draw a sketch of a solenoid buzzer design that uses only the materials below:
        •  wood, nails, hot glue/glue guns, drill/drill bits, sheet metal screws, enameled wire (10m of 28 gauge), sandpaper (and belt sander), saw (not really necessary), strips of springy magnetizable steel (approx 0.5" wide, 3" long), and a D.C. power source (set betwen 3V and 6V). 
        • With those materials, you will have to make a working solenoid buzzer, as shown in the video.
    • Or... Winter olympics physics?

    Until Next Class:  Have a great break!
    Class 11: Wednesday, 2/18/26

    Warm Up:  Another analogy for thinking about circuits -- Mr. Chase's Amazon Distribution Network analogy

    1.  What's the purpose of the circuit?

    2.  Who gets the energy?

    Today: 

    Until Next Class:  Quiz next class -- series and parallel circuit fill-in-the-blanks
    Class 10: Monday, 2/15/26

    Warm Up:  Let's solve these circuit puzzles.

    Today: 

    Until Next Class:  Take a physics break
    Class 9: Thursday, 2/12/26

    Warm Up:  The diagram on the right shows 3 circuits and 3 versions of the circuits where we pretend that water is flowing, not electrons.

    1. Match Each circuit to its analog (match it to the water version of that circuit).

    2. Which pumps and batteries on the right are able push out the most current? 

    3.  Which arrangement has the least current?

    4.  How many amps of current flow from each battery?

    Today: 

    Until Next Class:  Have a great weekend!
    Electrical-panel-fh17mar_576_06_401-1.jpg (1200×1200)Class 8: Tuesday, 2/10/26

    Warm Up: 

    The pictures on the right show breaker panels.

    1. What is the purpose of a breaker?

    2. How does an electrician decide how many breakers are needed?

    3.  Why are there different kinds of breakers?

     

    Today: 

    Until Next Class:  None
    Class 7: Friday, 2/6/26

    Warm Up:  How can you start a fire with a 9 Volt Battery and some steel?

     

    Today: 

    Until Next Class:  Test over the material on the 3 quizzes.  If you want, you can drop the three quiz scores.
    Class 6: Wednesday, 2/4/26

    Warm Up:  How does an electric fence work?

     

    Today: 

    Until Next Class:  Test next Tuesday over the material on the 3 quizzes.  If you want, you can replace the three quiz scores with your test score.
    Class 5: Monday, 2/2/26

    Warm Up:

    There is a "pith ball" hanging next to the Van de Graaff generator.  The pith ball is foam that is covered with a conductive, metallic paint.  What do you think will happen when the Van de Graaff generator builds up a strong negative charge?  Why?

    Today: 

    Until Next Class:  Last quiz of the unit -- like p. 13-14 in the handout
    Class 4: Thursday, 1/29/26

    Warm Up:

    What do you think will happen if we make John Travoltage rub his foot on the floor and then hold his hand by the doorknob?  Why?

    Today: 

    • Return Quizzes
    • Finish Notes:  Conductors and Insulators.  Everybody tries the electrophorus.  Does the electrophorus have to be touching the foam in order to work?  Video is int he playlist.
    • Shock yourself, repeatedly, with the electrophorus.  Explain what's happening to the charges and what the net charge of the plate is.
    • Practice Questions : p.11-12
    • Learn about Electric Fields
    • Unit 5 Handout: Electric Charge (PDF)

    Until Next Class:  Quiz next class, like pages 11-12
    Class 3: Tuesday, 1/27/26

    Warm Up:

     How does a Van de Graaff Generator Work?

    Today: 

    Until Next Class:  None
    Class 2: Friday, 1/23/26

    Warm Up:

    Which of the following can we say with certainty?  Why?

    A)  The balloons have the same net charge

    B)  The cat and the foam "peanuts" have opposite net charges.

    C)  Both A and B are correct.

    D)  None of these answers is (are) correct.

    Today: 

    Until Next Class:  Quiz -- like p.9-10 of handout
    Class 1: Wednesday, 1/21/26

    Warm Up:

    When you rub a balloon on your hair, why does the balloon then stick to the wall?

    Today: 

    Until Next Class:  Quiz

    Link to 1st Semester