A Summer Challenge >>> Some of you were interested in actually sending your own radio signals - I have no idea how -- but here are some sites that give instructions, and of course you can google your own:
Either of these directions involves buying several parts, an oscillator and a transistor and a board. Let me know if you get it going. And have a wonderful summer.
Light in Slow Motion (Remember in our textbook, it said that light is both a particle and a wave- if you watch the pulse of light in the Coke bottle, you can visualize how this is so. See it as a particle, a pulse, and then see it as a wave.)
On Monday we will probably be able to finish the radios, but likely we will have to wait till the following week to try them out. To make a homemade "ear bud" bring a tin can to class, and if you have a good magnet (neodymium) bring that. An old telephone receiver would be good, if you have one to donate.
Thank you for your patience in class yesterday; I think our project actually went as good as it could, kinda like a first draft on a writing project, and so if it did not go well for you, it probably will go much better when we do it over. I have never done this before myself, but I think this will be a fascinating and enlightening project; radio and television has always been just "magic"- what I mean is it made no sense to me. Hopefully, we will start to get glimmerings of how it works.
Here is a video from 1943--that's right in the middle of WWII!-- explaining how radio is broadcast. In your notes, copy the flow chart near the end (at 8 minutes) that shows the steps, even if you don't entirely understand. A Blast from the Past!
Here is a video that talks through all the steps of building a crystal radio; however, it is not precisely the same as the version we are making. We will be building the capacitor next; that is the paper towel tube with the aluminum foil/paper slider, so pay special attention to that. So, somehow get a hold of a paper towel tube by next Monday!
We will also need to find various sound amplifiers, like do you have an old corded phone in your junk pile? We may need to build some earphones, requiring strong magnets (neodymium)
This is a schematic of what we are going to build -- it's like a code --can you figure any of it out?
The parts are as follows: antenna, capacitor, coil, earphones, diode. (A diode is a little bitty part that makes all the electrons go in one direction only--like a one-way street.) We are missing a ground wire.
TEXTBOOK READING: If you finished watching the NASA videos having to do with the electromagnetic spectrum (from the last blog) , you may skim over chapter 13, section 2 from your textbook, and proceed to reading section 13.3 (chapter 13, section 3) pages 403-406 ONLY on radio and television communication.
If you did not yet watch all the videos from last blog, time to do so.
Homework is watching some short videos. This site has a playlist of 8 short videos on Electromagnetic Radiation. Watch all 8 (I have only watched the first one yet, but I think it must be good, 'cuz it's NASA,?) Maybe you should take a break half-way through. http://missionscience.nasa.gov/ems/emsVideo_01intro.html (
(sorry about the missing link -- computer problems! It's 32 minutes total time, but if you can only do the first half, that's fine. One thing to understand from these videos is how much we have been able to learn about the universe by "tuning in" to all the wavelengths of EM radiation.) Tak
Wonderful, wonderful evening of music last night! I doubt very much that you were thinking about how those sound waves traveled, or about fundamentals and overtones, about whether any nearby zoos were having trouble with their elephants, or it the wine glasses were in danger of shattering...I am so proud of all of you.
So here are the videos we missed yesterday; I was hoping to enjoy them together, but it was not to be... starting with the Power of the Pentatonic Scale...
And now for a commercial from our sponsors...
And a summary of this last chapter, but super-speed... (If you understand it all, you're a genius)
That's enough for Tuesday; on Wednesday, read the first section of the next chapter. Electromagnetic Waves, section 1. As you read, underline or highlight the summarizing sentences of each section. Here are two worksheets to assist you: https://drive.google.com/file/d/0B07s3-bcUr7tMmZkMmxxWTF2SEk/edit?usp=sharing *** If you are planning on taking a beach trip, get up early to do homework, or do all your homework on Tuesday.
I will give back your mousetrap cars on Thursday, but I also wanted to take pictures and play with them a bit. If you have yours still at home, would you bring it to class on Thursday?
Nicely done, it was fun. Thank you for your presentations yesterday. Homework for Monday is to continue reading till the end of the chapter and follow each section with the handout pages. Leave the last Review page for later. {If a certain person has misplaced their copy, I can't get you another one, because I misplaced the whole book! Taking really good notes could replace the worksheets, as well as the end-of-chapter assessment.}
If you recall, you were also supposed to look up the missed answers on last week's test, chapter 11.
My computer, along with bookmarks, is in the shop, so I'm keepin' it simple. Work hard on Friday, then enjoy the weekend.
I wrote the blog this morning, but it was somehow deleted. In brief, the homework was this, finish the musical instruments and be prepared to present it to the class, a short demonstration and how it works, 2 minutes max. The younger kids will be joining us, as they are also studying hearing/sound.
Then textbook reading, chapter 12 (Sounds) sections 2 and 3 (properties of sound / music) I did assign the worksheets that would go along with them, but if you need extra time, you can continue on Friday.
Sorry about the mix-up. And thanks, MD, for letting me know.
And we will be sharing our instruments with both our class and the youngers! so rehearse your demonstration--I'm sure your mom would love to be a practice audience. :) Just 2 minutes maximum; demonstrate your instrument and explain how it works.
Textbook Reading, Chapter 12 (Sound) sections 2 and 3: Properties of Sound/ Music. Worksheets which correspond are pages 18,26,27,30,and 31. Review your previously done worksheets.
That should be plenty! Hopefully you will do section 2 on Tuesday and section 3 on Wednesday, in order to retain more of what you've learned.
If you are still looking for ideas for a musical instrument, check the previous blog.
Friday, May 2, 2014
I know! It was a hard test! Consider it practice...although, if you did great, consider it an accomplishment:) Homework today is to find the answers to the problems you missed on the test, by searching your textbook, and to make OK answers better answers.This is to be written down. Use extra paper.
Homework also is to work on musical instruments:
Finding and choosing an instrument to make yourself. Not too easy; not too hard. Consider the limitations of your time, tools, and materials. Ask your mom whether she thinks it is a reasonable choice. Ask your dad too, and getting help is fine; anything dangerous like using power tool, have adult supervision.
Getting the materials
Building it.
Learn to play a simple song.
As you can see, this is a medium-sized project, so don't put it off.
Here are some resources (see also youtube, pinterest, and Google "homemade musical instruments") and from Instructables, here is a picture-list to browse from http://www.instructables.com/howto/musical+instruments/ -- LOTSSsss of ideas!
These are projects with directions and measurements, but you can also play them virtually online. Fun.
Tuesday, April 29, 2014
So, the test was difficult, and some of you did very well, but overall, I think we need to keep working on the material from the last section: reflection, refraction, diffraction, interference, standing waves and resonance. These are properties that all waves share, and so we will continue to discuss them when we learn about sound waves in music and when when we study waves in light. So first things first, watch Mr. Anderson's video: TAKE NOTES! In fact, jot down the six words above on six index cards, and add information as you watch...
(This is a video made for teachers to explain what it is they are supposed to be teaching.)
Textbook reading: Chapter 12, Sound section1. Fill in applicable worksheet from the packet handed out in class. - page 25 and 29. Be able to draw the ear from memory.
Lastly, research homemade musical instruments for ideas. Focus on an instrument which can play different pitches (notes) rather than only rhythm, and don't do an instrument where you fill up glass containers with water, since we will be doing this in class.) We will also talk more about this on Thursday, if you haven't come up with anything by then. Google, pinterest, or youtube, "homemade musical instruments". Your parents might be willing to "pitch" in for supplies (get it?) and as you recall, I have lots of PVC pipe, in case that helps (3/4").
And here is a short paragraph on what causes earthquakes. Notice that the names of the types of waves, compressional and transverse, are different. Can you tell which is which?
What causes earthquakes?
You might think Earth is a giant lump of rock, but you'd be wrong—it's more like a freshly
boiled egg: there's a hot, molten core bubbling away inside a
surprisingly thin outer crust. The countries we live in feel like
they're safely anchored on solid rocky foundations, but really
they're fixed to enormous rocky slabs called tectonic plates that can
slide around on the molten rock beneath. Imagine living your life on
an eggshell!
Earthquakes happen at places called faults (or fault lines) where the jagged
edges of two tectonic plates grind against one another. Most
earthquake activity happens in the middles of the oceans where plates
are pushing apart on the floor of the sea. Some of the most violent
earthquakes happen around the edges of a huge tectonic plate in the
Pacific Ocean, forming an intense area of activity known as the Ring
of Fire (so-called because there are many active volcanoes there
too).
Tectonic plates are constantly moving—in incredibly slow motion—and we don't even notice most
of the time. But every once in a while two grinding plates will suddenly
jolt into a new position. The energy released by this movement
creates an earthquake. It starts at a point inside Earth called the
focus where the moving plates are in contact, then travels
through the ground as very low-frequency sounds called shock waves
or seismic waves. The greatest damage happens at a place
called the epicenter, which is the point on Earth's surface
above the focus. Earthquakes continue until all the energy released
at the focus has been safely dissipated. Even then, there's still a
chance that further earthquakes, known as aftershocks, will
happen for some hours or even days afterward.
Seismic waves travel in two very different ways. Some of them, known as primary waves
(or p-waves), vibrate the ground in the direction in which the waves
themselves are moving. They travel in a similar way to ordinary sound
waves by alternately squeezing and stretching the ground in patterns
known as compressions and rarefactions. Waves like this are called
longitudinal waves and travel at incredible speeds of around 25,000
km/h (15,500 mph). There's another kind of seismic wave known as a
secondary wave (s-wave) that travels only half as fast. Unlike
p-waves, s-waves travel by making the ground vibrate up and down as
they move forward. It's because seismic waves travel at such
amazing speeds—broadly speaking, as fast as a rocket taking
off—that we get so little time to avoid quakes. Earth's diameter is
a little under 13,000 km (8,000 miles) at the equator, so a really
fast p-wave can theoretically shoot from one side of the planet to
the other in less than half an hour! Artwork: As s-waves travel forward, they shake the
Earth up and down or from side to side (at right angles to the direction
of motion). P-waves shake the Earth back and forth in the same
direction in which they're moving. An s-wave is
an example of a transverse wave; a p-wave is an example of a
longitudinal or compression wave.
This brings us to the end of chapter 11; there will be a test on Mondayon the material covered in the textbook. If you have questions, write them down; I will answer them at the beginning of class.
Thank God! It's Good Friday... and homework is limited. Please read chapter 11, section 2 - Wave Properties, for Monday's class. Take notes/make illustrations. And have a great Easter - You are all invited to Open Door's Good Friday service at Pioneer Park - David Harmon is speaking and Jesse & Jadon leading worship, Friday at noon.
Here are the two videos that I could not make work in class, the first one tells you another reason magnets are so amazing, and the second one tells you that it's not just about cool toys.
To prepare for Thursday, read in your textbook Chapter11, section 1, The Nature of Waves, take notes and answer the section 1 assessment questions on page 331 in your science journals.
When it was discovered, serendipitously, that an electric current induced a magnetic field in a wire, the question was asked, Could a magnetic field return the favor? And yes, with a lot of clever determination, Michael Faraday invented the generator, which he called the Dynamo, how cool is that name? Faraday demonstrated that a changing, or moving, magnetic field would induce an electric current. This is called electromagnetic induction.
Read your textbook, chapter 8, section 3: Producing Electric Current, taking notes/illustrate the main ideas and vocabulary listed under "As You Read" on page 240. And fill in the worksheets from class. After reading about generators, watch these videos:
3
Reminder: Do the worksheets handed out in class to reinforce your understanding of the textbook!
***[Hopefully, you are checking for homework on Friday--please do it today, and enjoy next week as a holiday.]
Turns out (no pun intended), that a motor is just short for a motion-maker. In class today, what we made was an item that turned on its axle. If we put a piece of tape on an end like a flag, that would be sorta like a fan (if you were an ant). We turned (again, no pun) electrical energy and magnetic force into kinetic energy, the energy of motion.
Continue to work on your motor until you have gotten it to work well. Here is the video to refer to:
Return to your textbook, and review the explanation of electric motors on page 237+. Particularly pay attention to the diagrams. In your lab journals, make a similar set of diagrams showing how your own home-made motor works, with detailed explanation for each illustration, and also N/S designations for the magnets. . Do you see the similarities as well as the differences between the book and your model?
Although we've described a number of different parts, you can think of a motor as having just two essential components:
There's a permanent magnet (or magnets) around the edge of the motor case that remains static, so it's called the stator of a motor.
Inside the stator, there's the coil, mounted on an axle that spins around at high speed—and this is called the rotor. The rotor also includes the commutator.
If we compare the typical motor to the motor we made, the magnet is the stator (it stays in one place) the coil is the rotor (it rotates) and the commutator, the part that keeps the coil moving in one direction rather than bobbing between north and south poles of the magnet-- on our motor it is the fact that we have insulation on half of one side of the coil end, which turns the power off and on. The axle is the ends that stick out of the coil. It looks cool if you twist the ends a bit, to make a twirly.
Have a very enjoyable spring break! Make the most of it!
Tuesday, March 25, 2014
1. Read (again) chapter 8, section 2 to review, and now I think, to understand, about how electricity and magnetism are related, and about electromagnets. Copy the illustrations and captions if you haven't yet done so, and try to explain to yourself or someone else the AS YOU READ list on page 233. The next thing we will learn about are motors, which combine electromagnets with permanent magnets to produce motion.
and now an old-timey video about electromagnetism. This is a one-hour program made out of 6 10-minute episodes. I have only watched the first two so far. It's an old-school cartoon, but the explanations are very helpful. Take some notes and illustrate. You just need to watch the first two episodes (twenty minutes,) but if you want to go on to the third episode, that's great.
Lastly, write a paragraph, and make illustrations, about Thursday's experiment. In your own words, tell what you were trying to do (start at the beginning) and what you may have discovered, the problems you encountered, the different things you tried, in order to discover the link between electricity and magnetism. Having watched the previous video, and perhaps referring to the reading from the last homework blog, give the best explanation you can.
An electric current induces...a ((((((((magnetic field)))))))
The homework post will be a little late this morning; if you would like to start reading, here is the article from the web--it is excellent, and if you can, print it out so that you can highlight and take notes from it:
Pictures are worth a thousand words, so pay attention to the pictures, and copy them, along with an explanation, into your science journals. Also pay attention to new vocabulary and write it down along with its definition and an example. Pick out the main ideas. You will forget everything you don't already know, unless you somehow interact with it, and what's the point in that?
I will post a few videos later on, but the "work" will be reading and note-taking. Come to class with questions!
Thursday, March 13, 2014
interesting...more on static electricity...you will learn more....than you ever thought possible....
7 minutes
AND now some amazing magnet stuff...
This video is awesome, even if it is probably over most of our heads...
and since that video probably made very little sense (but the narrator had the most amazing voice!) let's end on a fun and practical note...if anyone has the stuff described in the video, could you bring it to class on Monday? I would very much like to try out the toothbrush thing and the last bit with the ball bearings.
Now the real work begins>>>Read the textbook, chapter 8, section 2. Take notes in your science journals on vocabulary, write out the main points, "As You Read,"
and copy the illustrations. Use complete sentences, with the goal of producing something that you can look back on in future years and still remember what you learned.
Your homework is to read the first section of Chapter 8, Magnetism, paying attention to vocabulary and the As You Read topics listed at the beginning of the chapter, which should help you know what to take notes on in your science journals. Also pay a lot of attention to the illustrations, and copy them to your journal, along with explanation. Do the MiniLab on page 231; make an illustration and answer the questions in your lab journal. Answer the Section 1 assessment questions. When you answer a question, use complete sentences which re-state the question. [What I mean is, when the question asks you to describe what happens when you bring two like magnetic poles together, you don't just say, "1. They stick." You should write something like this: "When two like magnetic poles are brought together, they ...blablabla." This way, when you go back to review, your answer makes sense.] THE GOAL OF THIS HOMEWORK IS TO LEARN THROUGH NOTE-TAKING AND PICTURE-MAKING (drawing what you learn). If you just read, you will understand less and forget more. If you take notes, you will keep what you have learned, and even be able to teach others. I would love to see your lab journals become a record of your journey that you can be proud of. Perhaps this would be a good time to put your science notebooks in order, as well. Those of you who forgot "The Story So Far..." please remember on Thursday.
Monday's class will be the TOPS test, and so the best way to prepare for that is to review the packet and to fill out the Story So Far summaries (which should already be done), understanding the main points of each page. You will turn in The Story So Far along with the test.
Also for homework is to read the last section of Chapter 7, paying attention to vocabulary and the What You'll Learn topics, which you should write as notes & pictures in your science journals.
Lastly is the math worksheet from class; be sure to use the equations. Answers will be posted shortly. There is probably enough room to show your work on the page. [my way of remembering that 'I' stands for current is that 'I' looks like a wire, and a current travels through a wire.] Answer sheet here and if you've need another copy of the worksheet/equation sheet: Google this >>> www.sciencewithskinner.com/files/.../Electricity/OhmslawPractProblems....
1. video: What are volts, ohms, and amps? not a cartoon, but I think you'll get it...
2. Textbook- Chapter 7, section 2 Electric Current: makes notes on vocabulary and major concepts as described at the beginning of the section "As You Read" and also pay good attention to the pictures. In a science textbook, pictures are more important that words!
3. Do the math worksheet handed out in class.Remember that I want you to show your work. First write the correct form of the equation, then plug in the numbers, then underline or box the answer, which should INCLUDE UNITS! And this should be on a separate piece of paper, as I mentioned in class. [I will post an answer sheet in the comments below soon.]
The parts are as follows: antenna, capacitor, coil, earphones, diode. (A diode is a little bitty part that makes all the electrons go in one direction only--like a one-way street.) We are missing a ground wire.
