Study Guide Answers

Below you will find the abridged answers to the electrostatics study guide as well as a couple of problems we did together for bellwork.

Faraday Cages and Electrostatics Study Guide

Today we talked briefly about Faraday cages and why a car is a pretty good place to be during a lightning storm. We also watched a Top Gear video with a car being hit by lightning.


After that we counted and recorded your stamps from 2/6 until 3/24. Finally, we started work on your study guide. Thursday will be a work day and your test is on Friday.

Voltage and Electrical Potential Energy

First we compared gravitational potential energy to a new quantity, electrical potential energy.

Then we took some notes about electric potential, also known as voltage.

Your homework is Voltage.

Coulomb's Law

Today we derived Coulomb's Law by using an online simulation to collect data. Here is the lab:

Coulomb's Law Virtual Lab

We talked about the results of your lab to bring them together into Coulomb's Law, which we wrote on the board along with the bellwork from the beginning of class. It ended up being a little messy, but Coulomb's Law is in the top right corner area.

 Your homework is Concept-Development 32-1.

Practice: Electrostatics IV

Coming back from a three day weekend, I thought we could use some practice with what we've learned in this unit so far. So today we're just working on Electrostatics IV. Note that the last problem does not show up in the electronic copy; you must get a hard copy from school.

Polarization and Induction

Bellwork first:

Then we read pages 389-392 in the textbook and took notes on:

• charging by contact
• charging by induction
• ground/grounding
• charge polarization/electrically polarized
• what's special about water?
• Why does a charged balloon stick to a wall?

You could have also worked on your homeworks as you read: Electrostatics II and Electrostatics III.

We then saw some demonstrations about stuff in your reading:

• A balloon attracting polar water molecules. A great video explanation (that I did not make) is here. You can do the same thing at home with a faucet turned very low and a plastic comb you have run through dry hair a few times.
• A charged balloon attracts and then repels paper pieces
• Students acting like electrons are repelled by a negatively charged balloon or attracted by positively charged candy to induce a charge on one side of the room.

 

Conservation of Charge and Charging By Friction

Homework: Electrostatics I

The picture above is almost the same bellwork and notes as today, just last year. I'm including it because today's is so dark and my iPod is still crashing when I try to edit:

Electrostatics Lab

Today I gave you some balloons and some rabbit fur and set you loose to answer these questions:

Ignore the date; I just used the picture from last year.

Solving Compound Circuits

Solving a compound circuit starts with finding the total resistance like yesterday, but then we find the total current and trace it throughout. I wanted to take a video of this like yesterday, but I forgot to charge the camera, so I worked through the bellwork quickly on my computer at home. Here is the video for that.

Homework tonight is to finish the back of Concept-Development 35-2.

Electrostatics Study Guide

Today is your one day to work on the study guide. Abridged answers are below. Your test is Monday.

Faraday Cage and Study Guide

Today we talked briefly about Faraday cages and why a car is a pretty good place to be during a lightning storm. We also watched a Top Gear video with a car being hit by lightning.

After that we counted and recorded your stamps from 2/8 until today for Conceptual and from 2/28 until today for Honors. Finally, we started work on your study guide. Tomorrow will be a work day and your test is on Monday.

Electric Potential/Voltage

Electric potential - also called voltage - is the last thing that will be on your next test. Homework is Voltage and is due tomorrow.

Coulomb's Law Practice

We only had 20 minute periods today, so all we did was practice some Coulomb's Law problems.

Electrostatic Potential Energy

Today we talked very briefly about electrical potential energy. No homework tonight.

Coulomb's Law

Today we used some fabricated data to derive Coulomb's Law. Your homework for the weekend is Concept-Development 32-1.

Practice: Electrostatics IV

First, we watched a demo and explained it for bellwork. A video of the demo and explanation is here, and a picture of the board at the end is below. Then we worked on Electrostatics IV, which is due tomorrow. There is a #7 on this assignment that does not show up in the link.

Charging by Induction

Today we did a silly activity to show charging by induction. Everyone was a proton or an electron in a conductor connected to the ground. I scared some of the electrons away into the ground with a negatively charged balloon to leave the conductor with a positive net charge. Then I attracted some electrons out of the ground into the conductor with positively charged candy, leaving the conductor with a negative net charge.

Homework tonight is Electrostatics III.

Polarization

Welcome back! In addition to the bellwork/notes below, we watched a demonstration of a balloon attracting polar water molecules. A great video explanation (that I did not make) is here. You can do the same thing at home with a faucet turned very low and a plastic comb you have run through dry hair a few times. Homework tonight is Electrostatics II.

Conservation of Charge and Charging By Friction

Homework: Electrostatics I. The printers have been down all week so you had to copy this onto your own paper. You can also click on that link and print out the GoogleDoc.

EDIT: Printing resumed during ECAP, so only 2nd period did not get copies of the homework.

Electrostatics Intro Lab

Today I gave you some balloons and some rabbit fur and set you loose to answer these questions: