Electric Potential Energy and Potential Difference

Today we talked about the energy stored by a charge when you move it in relation to another charge.

Notes: Electric Potential Energy and Electric Potential

There is no school tomorrow and Monday is a sequential schedule.

Homework is Electricity TIPERs #3.

Coulomb's Law

So, we already know that like charges repel and unlike charges attract. Today we learned an equation to calculate the force with with charges attract or repel.

Notes: Coulomb's Law

Here is an old video of me demonstrating #3 on the bellwork: Balloon and Paper Pieces.

Homework tonight is Electricity TIPERs #2.

Charge Conservation

Today we started our last unit: Electricity. We began by conducting a qualitative lab with pieces of tape, aluminium foil, and paper: Sticky Tape Activity. Please note that the first two pages are instructions, then the rest of the pages have places to make you diagrams and write your answers. This packet does count as a lab grade, so don't forget to turn it in.

Later we used your results to talk about charge, moving charge around, and polarization/induction.

Notes: Charge Conservation

I might have bent some water in class. Here is a video of that: Balloon Attracts Water


Your homework tonight is Electricity TIPERs #1 (email miss.volkening@gmail.com for a copy)

Test: Sound and Standing Waves

Your test is today! Have a good and restful spring break!

Work Day

A lot of you are gone for the Reading Buddies field trip, so today is a work day. At 10 AM you had the opportunity to go to the track and observe 17 minutes of silence in honor of the victims of the school shooting in Florida last month.

Your test is tomorrow and your speed of sound lab is also due tomorrow.

Lab: Speed of Sound in Air

Today you are completing a lab to verify the speed of sound in air:

Lab: Speed of Sound in Air

Here are some tips/reminders that were on the board:

If you missed this lab, there is a way to do it online, but it's a bit involved. You will have to use two different simulators.

This simulator is the best because it explains the lab and most closely emulates the physical process involved: http://physics.bu.edu/~duffy/HTML5/speed_of_sound.html

The only problem is that it only has 3 available frequencies, and we need at least 6 for a good graph. So while I want you to play with this applet, I want you to actually get your data with a different applet:

http://www.physics.smu.edu/~olness/www/05fall1320/applet/pipe-waves.html

You will need to follow the download instructions and run it off of your computer, not in the web browser window. It may not want to run at first because it uses an old version of Java, but just keep hitting “run anyway” and it will work. In the applet, choose “one side open” under "Form of tube" and make sure "Vibrational mode" is set to "Fundamental." Then you can put in different lengths of tubes and write down the frequencies it gives. This is sort of backwards from the real lab, in which we are choosing frequencies and finding the corresponding lengths of tubes, but you will get the same frequency vs. length data in the end.

You also received a practice test for your test on Thursday:

Sound and Standing Waves Practice Test

Wednesday will be a work day.

Pre-Lab and Work Time

Today you first took back your 2015 FRQ 5 from earlier this week and graded it yourself. You then turned that back in and you will receive participation points for completing it and grading it.

Next we talked about the lab we'll be doing next week and gave you time to work on the pre-lab and lab procedure. Please be ready to start taking data next class.

Lab: Finding the Speed of Sound in Air

Miscellaneous

Today we just looked at a few things that I didn't have time for earlier in the week:

Harmonic Waveform Generator from meettechniek.info
Michael Norris: Harmonic Series Calculator

Veratasium: 2-D Ruben's Tube

Steve Mould: Laser + Mirror + Sound (we only watched the first 5 minutes or so)

Brusspup: Amazing Water and Sound Experiment

You do not have any homework tonight. If you are missing any homework, especially for this unit, please work on that.

Coming up:

• You have a test next week on Thursday. Several of you have told me you will be gone for school business; you might want to take it early on Wednesday after school. The test grade will not go on the quarter grade.
• You have a lab on Monday/Tuesday that you will be turning in instead of just getting it checked. It will not go on the quarter grade.
• You have a work day and a practice test tomorrow
• The last day of the quarter is Thursday. I have to submit quarter grades on Friday. If you want something to make it on to the quarter grade, you need to turn it in soon.

Standing Waves Part 2

Today we discussed the standing longitudinal waves that can form inside a hollow tube. This is how wind-based instruments work.

Notes: Standing Waves Part 2

Homework is p.506 CON #10 + p.510 #51 & 52a

Standing Waves Part 1

Today we started talking about standing waves and how stringed instruments create certain frequencies.

Notes: Standing Waves Part 1

There are a lot of sites we visited and videos that we watched; they are linked in the Powerpoint.

Homework is in two parts and you probably got a good start in class:
p.510 #41 & 46
AND
2015 FRQ 5 (this is an old FRQ from the AP test).

These are due THURSDAY because of the SAT on Wednesday. I would rather that you focus on the SAT now and do these Wednesday night.

Resonance and Beats

Today is another mostly conceptual day:

Notes: Resonance and Beats

Homework is p.505 Multiple Choice #9 + Conceptual #6 & 11

For those that asked, here is the video of the boy breaking the glass:

Boy Breaks Glass With Voice

If you try this yourself, PLEASE wear eye protection and do not use someone's nice glasses. Go get some wine glasses from a thrift store or something.

Doppler Effect

The Doppler Effect is one of my favorite things!

Notes: Doppler Effect

Homework is Ch. 14 (p. 505) Multiple Choice #12 + Conceptual #1, 7, 8