Electrostatics Test

I hope you all used the practice exam to study for your test today!

Work Time

Tomorrow is your electrostatics test, so today is your usual one day of work time.

Remember that this week is sequential because we have Friday off.

Flow of Charge and Practice Exam

We started the day with one question on bellwork: Why can bird stand on a high-voltage power line without getting shocked?

This lead to a discussion of electricity, which is actually our next unit. When you don't have a potential difference, no charges flow and therefore there is no electricity. Watch this video of some kids touching an electric fence; until the last dude, all of those kids were at the same potential, insulated from a different potential (ground), so there was no electricity flowing through them.

After that we started working on the electrostatics practice exam.  Unfortunately some of the content is copyrighted, so although I CAN give it to my students I CANNOT post it on the internet. Email me at miss.volkening@gmail.com for a copy. 

Next week is sequential, so Monday will be a work day and Tuesday will be your test.

Solutions To Practice Exam

Solutions Videos:
#4
Placing the Third Charge
Induction on Conducting Spheres

Relationship Between V and E

Today we discussed the relationship between electric potential (V) and electric field (E). We also mentioned electric force (F).

Notes!

Your homework is another worksheet; this one says Homework 3/26 right under the place for your name.

If you need any electronic copies of the worksheets (there was one we worked on during class, too) email me at miss.volkening@gmail.com.

Electric Potential Energy and Electric Potential

We are finishing out this unit, but today's topic will be very important in the next unit.

Notes: Electric Potential Energy and Electric Potential

Homework tonight is a worksheet I made for you. The front can be found here, but the back is a ranking task that is copyrighted so I cannot put a copy here.

Electric Fields and Electric Field Lines

Welcome back! We reviewed Coulomb's Law in bellwork and then jumped right back into electrostatics with electric field:

Notes: Electric Fields (remember to download and run as a slideshow)

There was a fair amount of drawing that also happened on the board to explain why charged tends to accumulate at the pointy bits of conductors; I suggest reading section 15.6 if you missed that part.

Homework is Chapter 15 (p. 543) #17, 19, 30, 34

Coulomb's Law Practice

Today is the last day of the quarter and the last day before spring break. I know some of you are gone today, some want to get missing work in to raise your grade, and some are just checked out, so today all we did was work on some Coulomb's Law practice problems. This problem set is officially due when we get back from break but you might finish in class.

Chapter 15 (p. 542) #7, 8, 9, 10, 11, 15

Coulomb's Law

Today we talked about Coulomb's Law and polarization.

Notes: Coulomb's Law

Coulomb's Law is the most math-intensive part of this unit, so we will also be practicing Coulomb's Law problems tomorrow. Remember that tomorrow is the last day of the quarter, so if you have anything you want to get onto the quarter grade, turn it in now. I will do my best to grade everything that is turned in before I go home on Thursday, but I might not make it. The earlier you turn in your work, the sooner I'll get to it.

Homework tonight is Chapter 15 (p. 541) #1 & 4

Electrostatics Intro

Today we introduced the electrostatic unit by making balloons attract and repel, then talking about why what we did worked. The explanation involves net charge, transfer of electrons, and the fact that like charges repel and unlike charges attract.

Then people started on their homework while I passed out missing assignment reports and took care of assignments people found.

Homework is in two parts:

Chapter 15 Conceptual #1 & 2 - you will turn this in tomorrow
Read Sections 15.1 & 15.2 and take notes. These will NOT be collected.

Chapter 14 Practice Exam

Monday is your test for this chapter, so below you will find our usual practice exam and solutions videos. This test is shorter than normal, consisting of 9 multiple choice problems and two free response; think of it more like a quiz than a test.

Ch. 14 Practice Exam

Answer Key:
1. 817 Hz
2. 38 m/s

Solutions Videos:
#1
#2

Remember that your Speed of Sound in Air lab is due Monday.

Lab: Speed of Sound in Air

Today you are working on your lab! You can find a copy of the lab here.

On the board there were some hints to help you finish in time, but you can also work on this tomorrow when I give out the practice exam.

There is no additional homework. The lab is due Monday.

Resonance and Beats

Today we are going over the last two topics in this unit: resonance and beats. We've already touched on both of these, but here are some notes:

Notes: Resonance and Beats

Tomorrow we are doing a lab, so tonight's homework is to do the pre-lab.

Lab: Finding the Speed of Sound in Air

On Friday I will pass out a practice test and you may also continue to work on your lab, which will be due Monday. Your test for this unit is currently scheduled for Monday.

Standing Waves

Today we talked all about standing waves:

Notes - download and run as a slideshow

We will be using the information about the standing waves produced in a tube closed on one end for a lab next class.

Homework is Ch. 14 (p. 509) #38, 41, 49, 53