Hot Air Balloon

Monday May 31, 2010

About 400 years ago, Leonardo da Vinci wanted to fly… so he studied the only flying things around at that time: birds and insects. Then he did what any normal kid would do—he drew pictures of flying machines!


Centuries later, a toy company found his drawing for an ornithopter, a machine that flew by flapping its wings (unlike an airplane, which has non-moving wings). The problem (and secret to the toy’s popularity) was that with its wing-flapping design, the ornithopter could not be steered and was unpredictable: It zoomed, dipped, rolled, and looped through the sky. Sick bags, anyone?


Hot air balloons that took people into the air first lifted off the ground in the 1780s, shortly after Leonardo da Vinci’s plans for the ornithopter took flight. While limited seating and steering were still major problems to overcome, let’s get a feeling for what our scientific forefathers experienced as we make a balloon that can soar high into the morning sky.


Materials: A lightweight plastic garbage bag, duct or masking tape, a hand-held hair dryer. And a COLD morning.


Here’s what you do:


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Diaper Wind Bag

Monday May 31, 2010

Lots of science toy companies will sell you this experiment, but why not make your own? You’ll need to find a loooooong bag, which is why we recommend a diaper genie. A diaper genie is a 25′ long plastic bag, only both ends are open so it’s more like a tube. You can get three 8-foot bags out of one pack.


Kids have a tendency to shove the bag right up to their face and blow, cutting off the air flow from the surrounding air into the bag. When they figure out this experiment and perform it correctly, this is one of those oooh-ahhh experiments that will leave your kids with eyes as big as dinner plates.


Here’s what you do:


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Genie in a Bottle

Monday May 31, 2010

While this isn’t actually an air-pressure experiment but more of an activity in density, really, it’s still a great visual demonstration of why Hot Air Balloons rise on cold mornings.


Imagine a glass of hot water and a glass of cold water sitting on a table, side by side. Now imagine you have a way to count the number of water molecules in each glass. Which glass has more water molecules?


The glass of cold water has way more molecules… but why? The cold water is more dense than the hot water. Warmer stuff tends to rise because it’s less dense than colder stuff and that’s why the hot air balloon in experiment 1.10 floated up to the sky.


Clouds form as warm air carrying moisture rises within cooler air. As the warm, wet air rises, it cools and begins to condense, releasing energy that keeps the air warmer than its surroundings. Therefore, it continues to rise. Sometimes, in places like Florida, this process continues long enough for thunderclouds to form. Let’s do an experiment to better visualize this idea.


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Soda Can Trick

Monday May 31, 2010

When air moves, the air pressure decreases. This creates a lower air pressure pocket right between the cans relative to the surrounding air. Because higher pressure pushes, the cans clink together. Just remember – whenever there’s a difference in pressure, the higher pressure pushes.


You will need about 25 straws and two empty soda cans or other lightweight containers


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Going Further with Advanced Chemistry

Monday May 31, 2010

This experiment is for advanced students.


One of my best teaching tools for science developed from a brain freeze one afternoon in class. I went to the board to draw the chlorophyll wheel and drew a complete blank.


“Let’s say I forgot how to draw the wheel.” I turned to the class, marker in hand, and scanned the room. Puzzled faces, the blank faces I expected, but, what was that? A few smiles scattered about the room.


As I pulled out and some volunteered info, we got into that wheel. They also found that it was easier to know what to do next than to have me tell them to find it in their book and be prepared…I was coming back to them. Students frantically finding the wheel in their biology books so they were armed when I came to them.


It was a great experience, and my lectures were a lot more fun and interactive from then on.


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Air Takes Space

Monday May 31, 2010

You’re about to play with one of the first methods of underwater breathing developed for scuba divers hundreds of years ago.! Back then, scientists would invert a very large clear, bell-shaped jar over a diver standing on a platform, then lower the whole thing into the water. Everyone thought this was a great idea, until the diver ran out of breathable air…


Materials: 12″ flexible tubing, two clear plastic cups, bathtub


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Advanced Alternative Energy Exercises

Saturday May 1, 2010

Let’s see how much you’ve picked up with these experiments and the reading – answer as best as you can. (No peeking at the answers until you’re done!) Just relax and see what jumps to mind when you read the question. You can also print these out and jot down your answers in your science notebook.


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Answers to Advanced Alternative Energy Exercises

Saturday May 1, 2010

Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!


Here’s printer-friendly versions of the exercises and answers for you to print out: Simply click here for printable questions and answers.


Answers:
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Solar Cookies

Saturday May 1, 2010

Can you use the power of the sun without using solar cells? You bet! We’re going to focus the incoming light down into a heat-absorbing box that will actually cook your food for you.


Remember from Unit 9 how we learned about photons (packets of light)?  Sunlight at the Earth’s surface is mostly in the visible and near-infrared (IR) part of the spectrum, with a small part in the near-ultraviolet (UV). The UV light has more energy than the IR, although it’s the IR that you feel as heat.


We’re going to use both to bake cookies in our homemade solar oven. There are two different designs – one uses a pizza box and the other is more like a light funnel. Which one works best for you?


  • Two large sheets of poster board (black is best)
  • Aluminum foil
  • Plastic wrap
  • Black construction paper
  • Cardboard box
  • Pizza box (clean!)
  • Tape & scissors
  • Reusable plastic baggies
  • Cookie dough (your favorite)
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Solar Boat

Saturday May 1, 2010

expansionpacks_clip_image004_0000Does it really matter what angle the solar cell makes with the incoming sunlight? If so, does it matter much? When the sun moves across the sky, solar cells on a house receive different amounts of sunlight. You’re going to find out exactly how much this varies by building your own solar boat.


We’re going to use solar cells and the basic ideas from Unit 10 (Electricity & Robotics) to build a solar-powered race car.  You’ll need to find these items below.  Note – if you have trouble locating parts, check the shopping list for information on how to order it straight from us.


  • Solar motor
  • Solar cell
  • Foam block (about 6” long)
  • Alligator clip leads
  • Propeller (you can rip one off an old small personal fan or old toy, or find them at hobby stores)

Here’s what you do:


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Solar Car

Saturday May 1, 2010

solarboatSolar energy (power) refers to collecting this energy and storing it for another use, like driving a car. The sun blasts 174 x 1015 watts (which is 174,000,000,000,000,000 watts) of energy through radiation to the earth, but only 70% of that amount actually makes it to the surface. And since the surface of the earth is mostly water, both in ocean and cloud form, only a small fraction of the total amount makes it to land.


A solar cell converts sunlight straight into electricity. Most satellites are powered by large solar panel arrays in space, as sunlight is cheap and readily available out there. While solar cells seem ‘new’ and modern today, the first ones were created in the 1880s, but were a mere 1% efficient. (Today, they get as high as 35%.) A solar cell’s efficiency is a measure of how much sunlight the cell converts into electrical energy.


We’re going to use solar cells and the basic ideas from Unit 10 (Electricity & Robotics) to build a solar-powered race car.  You’ll need to find these items below.  Note – if you have trouble locating parts, check the shopping list for information on how to order it straight from us.


  • Solar cell
  • Solar motor
  • Foam block (about 6” long)
  • Alligator clip leads
  • 2 straws (optional)
  • 2 wooden skewers (optional)
  • 4 milk jug lids or film can tops
  • Set of gears, one of which fits onto your motor shaft (most solar motor kits come with a set), or rip a set out of an old toy

Here’s what you do:


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Wind Turbine

Saturday May 1, 2010

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Believe it or not, most of the electricity you use comes from moving magnets around coils of wire! Wind turbines spin big coils of wire around very powerful magnets (or very powerful magnets around big coils of wire) by capturing the flow.


Here’s how it works: when a propeller is placed in a moving fluid (like the water from your sink or wind from your hair dryer), the propeller turns. If you attach the propeller to a motor shaft, the motor will rotate, which has coils of wire and magnets inside. The faster the shaft turns, the more the magnets create an electrical current.


The electricity to power your computer, your lights, your air conditioning, your radio or whatever, comes from spinning magnets or wires! Refer to Unit 11 for more detail about how moving magnets create electricity.


We’re going to build a wind turbine that will actually give you different amounts of electricity depending on which way your propeller is facing. Ready?


You’ll need to find these items below.  Note – if you have trouble locating parts, check the shopping list for information on how to order it straight from us.


  • A digital Multimeter
  • Alligator clip leads
  • 1.5-3V DC Motor
  • 9-18VDC Motor
  • Bi-polar LED
  • Foam block (about 6” long)
  • Propeller from old toy or cheap fan, or balsa wood airplane

Here’s what you do:


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Marshmallow Roaster

Saturday May 1, 2010

Do you like marshmallows cooked over a campfire? What if you don’t have a campfire, though? We’ll solve that problem by building our own food roaster – you can roast hot dogs, marshmallows, anything you want. And it’s battery-free, as this device is powered by the sun.


NOTE: This roaster is powerful enough to start fires! Use with adult supervision and a fire extinguisher handy.


If you’re roasting marshmallows, remember that they are white – the most reflective color you can get.  If you coat your marshmallows with something darker (chocolate, perhaps?), your marshmallow will absorb the incoming light instead of reflecting it.


Here’s what you need to get:


  • 7×10” page magnifier (Fresnel lens)
  • Cardboard box, about a 10” cube
  • Aluminum foil
  • Hot glue, razor, scissors, tape
  • Wooden skewers (BBQ-style)
  • Chocolate, marshmallows, & graham crackers

Here’s what you do:



Download Student Worksheet & Exercises


How does it do that? The Fresnel lens is a lot like a magnifying glass.  In Unit 9, we learned how convex lenses are thicker in the middle (you can feel it with your fingers).  A Fresnel lens (first used in the 1800s to focus the beam in a lighthouse) has lots of ridges you can feel with your fingers.  It’s basically a series of magnifying lenses stacked together in rings (like in a tree trunk) to magnify an image.


The best thing about Fresnel lenses is that they are lightweight, so they can be very large (which is why light houses used these designs). Fresnel lenses curve to keep the focus at the same point, no matter close your light source is.


The Fresnel lens in this project is focusing the incoming sunlight much more powerfully than a regular hand held magnifier. But focusing the light is only part of the story with your roaster.  The other part is how your food cooks as the light hits it.  If your food is light-colored, it’s going to cook slower than darker (or charred) food. Notice how the burnt spots on your food heat up more quickly!


Scientifically Dissecting a Marshmallow

Plants take in energy (from the sun), water, and carbon dioxide (which is carbon and oxygen) and create sugar, giving off the oxygen. In other words: carbon + water + energy = sugar


  1. In this experiment, we will reverse this equation, by roasting a marshmallow, which is mostly sugar.
  2. When you roast your marshmallow, first notice the black color. This is the carbon.
  3. Next notice the heat and light given off. These are two forms of energy.
  4. Finally, put the roasting marshmallow if a mason jar. Notice that condensation forms on the sides. This is the water.

So, by roasting the marshmallow, we showed: sugar = carbon + water + energy!


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Steamboats

Saturday May 1, 2010

In 1920’s, these were a big hit. They were originally called “Putt Putt Steam Boats”, and were fascinating toys for adults and kids alike. We’ll be making our own version that will chug along for hours. This is a classic demonstration for learning about heat, energy, and how to get your kids to take a bath.



Here’s what you need to build your own:


  • Copper tubing (1/8”-1/4” dia x 12” long)
  • Votive candle
  • Foam block
  • Scissors or razor (with adult help)
  • Bathtub

Here’s what you need to do:



Download Student Worksheet & Exercises


  1. Wrap the copper tubing 2-3 times around a thick marker. You want to create a ‘coil’ with the tubing. Do this slowly so you don’t kink the tubing. End with two 3” parallel tails. (This is easier if you start in the middle of the tubing and work outwards in both directions.)
  2. Stick each tail through a block of foam. Bend the wires to they run along the length of the bottom of the boat, slightly pointed upwards. (You can also use a plastic bottle cut in half.)
  3. Position a votive candle on the topside of the boat and angle the coil so it sits right where the flame will be.
  4. To start your boat, fill the bathtub with water. While your tub fills, hold the tubing in the running water and completely fill the coil with water.
  5. Have your adult helper light the candle. In a moment, you should hear the ‘putt putt’ sounds of the boat working!
  6. Troubleshooting: if your boat doesn’t work, it could be a few things:
    1. The tubing has an air bubble. In this case, suck on one of the ends like a straw to draw in more water. Heating an air bubble will not make the boat move – it needs to be completely filled with water.
    2. Your coil is not hot enough. You need the water to turn into steam, and in order for this to happen, you have to heat the coil as hot as you can. Move the coil into a better position to get heat from the flame.
    3. The exhaust pipes are angled down. You want the stem to move up and out of your pipes, not get sucked back in. Adjust the exit tubing tails so they point slightly upwards.

How Do They Work? Your steam boat uses a votive candle as a heat source to heat the water inside the copper tubing (which is your boiling chamber). When the water is heated to steam, the steam pushes out the tube at the back with a small burst of energy, which pushes the boat forward.


Since your chamber is small, you only get a short ‘puff’ of energy. After the steam zips out, it creates a low pressure where it once was inside the tube, and this draws in fresh, cool water from the tub. The candle then heats this new water until steam and POP! it goes out the back, which in turn draws in more cool water to be heated… and on it goes. The ‘clicking’ or ‘putt putt’ noise you hear is the steam shooting out the back. This is go on until you either run out of water or heat.


Bonus! Here’s a video from a member that colored the water inside the pipe so they could see when it got pushed out! Note that the boat usually runs as fast as the first video on this page. The boats here are getting warmed up, ready to go, so they only do one or two puffs before they really start up.



Exercises Answer the questions below:


  1. Name three sources of renewable or alternative energy:
  2. Why is it important to look for renewable sources of energy?
  3. What is one example of a fossil fuel?
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Solar Battery

Saturday May 1, 2010

This is the kind of energy most people think of when you mention ‘alternative energy’, and for good reason! Without the sun, none of anything you see around you could be here. Plants have known forever how to take the energy and turn it into usable stuff… so why can’t we?


The truth is that we can. While normally it takes factories the size of a city block to make a silicon solar cell, we’ll be making a copper solar cell after a quick trip to the hardware store. We’re going to modify the copper into a form that will allow it to react with sunlight the same way silicon does. The image shown here is the type of copper we’re going to make on the stovetop.


This solar cell is a real battery, and you’ll find that even in a dark room, you’ll be able to measure a tiny amount of current. However, even in bright sunlight, you’d need 80 million of these to light a regular incandescent bulb.


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Crystal Radio

Saturday May 1, 2010

xtal3This project is for advanced students. A crystal radio is among the simplest of radio receivers – there’s no battery or power source, and nearly no moving parts. The source of power comes directly from the radio waves themselves.


The crystal radio turns the radio signal directly into a signal that the human ear can detect. Your crystal radio detects in the AM band that have been traveling from stations (transmitters) thousands of miles away. After working with the electromagnetic spectrum in Unit 9 where we played with frequency and wavelengths of light, you’ll find that you’ve got all the basics for picking up AM radio stations using simple equipment from an electronics store.


The radio is made up of a tuning coil (magnet wire wrapped around a toilet paper tube), a detector (germanium diode) and crystal earphones, and an antenna wire.


One of the biggest challenges with detecting low-power radio waves is that there is no amplifier on the radio to boost the signal strength. You’ll soon figure out that you need to find the quietest spot in your house away from any transmitters (and loud noises) that might interfere with the reception when you build one of these.


One of things you’ll have is to figure out the best antenna length to produce the clearest, strongest radio signal in your crystal radio. I’m going to walk you through making three different crystal radio designs.


Materials:


  • Toilet paper tube
  • Magnet wire
  • Germanium diode: 1N34A
  • 4.7k-ohm resistor
  • Alligator clip test leads
  • 100’ stranded insulated wire (for the antenna)
  • Scrap of cardboard
  • Brass fasteners (3-4)
  • Telephone handset or get a crystal earphone

Here’s what you do:


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BEAM Robots

Saturday May 1, 2010

This project is for advanced students.This is one of the coolest applications of renewable energy to come about in recent years. BEAM stands for Biology, Electronics, Aesthetics, and Mechanics. It basically refers to a class of robots that instead of having complicated brains, rely on nervous-system type of sensors to interact with their world.


Some BEAM robots skitter, dance, flash, jump, roll, or walk, and most are solar powered. The result is a fast responding robot made of old cell phone parts that can fit inside your hand. We’ll be making a few different types so you can get a good handle on this type of programming-free, battery-free robotics.


Most BEAM robots use the same solar ‘engine’. The solar cell will convert sunlight into electricity, which will then be stored in our capacitors (think ‘electricity tanks’) until a certain threshold is reached… when the tanks are full, the robot begins to move. This means that you can leave them out all day, and they will sit and collect energy, then turn on by themselves until they run out of juice, then turn off, sit and recharge until they have enough energy to go again… and off they go!


Let’s walk through how to make a BEAM robot. Once you’ve got the hang of it, make a second solar engine from the rest of your parts and add any kind of body you want!


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Bristle Brush Bot

Saturday May 1, 2010

This is the simplest robot you can make… out of old parts from around the house. While this little robot doesn’t use energy from the sun or wind, we’ve placed it here with other alternative energy projects because the parts come from the trash bin.


This project is an extension of the Jigglebot robot from Unit 10.


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Stirling Engine

Saturday May 1, 2010

This project is for advanced students.This Stirling Engine project is a very advanced project that requires skill, patience, and troubleshooting persistence in order to work right.  Find yourself a seasoned Do-It-Yourself type of adult (someone who loves to fix things or tinker in the garage) before you start working on this project,  or you’ll go crazy with nit-picky things that will keep the engine from operating correctly.  This makes an excellent project for a weekend.


Developed in 1810s, this engine was widely used because it was quiet and could use almost anything as a heat source. This kind of heat engine squishes and expands air to do mechanical work. There’s a heat source (the candle) that adds energy to your system, and the result is your shaft spins (CD).


This engine converts the expansion and compression of gases into something that moves (the piston) and rotates (the crankshaft). Your car engine uses internal combustion to generate the expansion and compression cycles, whereas this heat engine has an external heat source.


This experiment is great for chemistry students learning about Charles’s Law, which is also known as the Law of Volumes, which describes how gases tend to expand when they are heated and can be mathematically written like this:



where V = volume, and T = temperature. So as temperature increases, volume also increases. In the experiment you’re about to do, you will see how heating the air causes the diaphragm to expand which turns the crank.


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Fuel Cell Power

Saturday May 1, 2010

41wpr5+y2qLThis project is for advanced students. We’re going to build a car that runs entirely on sunlight and water.  Use energy from the sun, we’ll first use a solar cell to convert sunlight into electricity.


Then we’ll use that electricity to split the water molecule (H2O) into hydrogen and oxygen atoms and store them in separate tanks.


Lastly, we’ll flip the system around to allow the hydrogen and oxygen gases to mix, which will produce the power to run the car and create an exhaust product that’s just plain water.


How does that sound?
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BEAM Robot: Solar Roller

Saturday May 1, 2010

Note: Brian Cox has created a BEAM Bot kit as an alternative BEAM project.

Brian's BEAM BOT is modeled after small BEAM projects where parts are soldered to each other, but such projects can be difficult to solder.

BEAM Bot uses a standard Printed Circuit Board (PCB) as the frame thus making it easier to assemble.

You can order Brian's BEAM Bot Kit here: fvresearch.com/product/beam-bot .

Click here for Brian's BEAM Bot instructional video (which can be found under Unit 25).

This project is for advanced students.This is one of the coolest applications of renewable energy to come about in recent years. BEAM stands for Biology, Electronics, Aesthetics, and Mechanics. It basically refers to a class of robots that instead of having complicated brains, rely on nervous-system type of sensors to interact with their world.

Some BEAM robots skitter, dance, flash, jump, roll, or walk, and most are solar powered. The result is a fast responding robot made of old cell phone parts that can fit inside your hand. We'll be making a few different types so you can get a good handle on this type of programming-free, battery-free robotics.

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BEAM Robot: Trimet

Saturday May 1, 2010

Note: Brian Cox has created a BEAM Bot kit as an alternative to the Trimet project.

Brian's BEAM BOT is modeled after small BEAM projects where parts are soldered to each other, but such projects can be difficult to solder.

BEAM Bot uses a standard Printed Circuit Board (PCB) as the frame thus making it easier to assemble.

You can order Brian's BEAM Bot Kit here: fvresearch.com/product/beam-bot .

Click here for Brian's BEAM Bot instructional video (which can be found under Unit 25).

This project is for advanced students. This is one of the coolest applications of renewable energy to come about in recent years. BEAM stands for Biology, Electronics, Aesthetics, and Mechanics. It basically refers to a class of robots that instead of having complicated brains, rely on nervous-system type of sensors to interact with their world.

Some BEAM robots skitter, dance, flash, jump, roll, or walk, and most are solar powered. The result is a fast responding robot made of old cell phone parts that can fit inside your hand. We'll be making a few different types so you can get a good handle on this type of programming-free, battery-free robotics.

You'll need to get the Trimet Kit from Solarbotics. It has everything you need except the tools for the job (soldering iron, pliers, wire strippers, razor) and paperclips.

Here's what you do:

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BEAM Robot: MiniBall

Saturday May 1, 2010

This project is for advanced students.This is one of the coolest applications of renewable energy to come about in recent years. BEAM stands for Biology, Electronics, Aesthetics, and Mechanics. It basically refers to a class of robots that instead of having complicated brains, rely on nervous-system type of sensors to interact with their world.

Some BEAM robots skitter, dance, flash, jump, roll, or walk, and most are solar powered. The result is a fast responding robot made of old cell phone parts that can fit inside your hand. We'll be making a few different types so you can get a good handle on this type of programming-free, battery-free robotics.

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Lesson 2: Advanced Alternative Energy Video

Saturday May 1, 2010

What’s all the hype about “Alternative Energy”? Are there really better ways of making the same energy for less? Absolutely! One of the biggest challenges we have right now is how to extract the energy that’s already around us. For example, the amount of energy in a gallon of water could power all of the USA for a year, if we only knew how to harness it safely.


There are many different forms of energy floating around you right now: solar batteries capture the heat and light energy from the sun and store it for later use; geothermal energy uses the difference in temperature to do work; the energy from rushing winds and rivers can be used to turn a motor; and the energy inside light waves themselves can be tapped into so you can hear radio signals using a battery-free radio.


We’re going to cover all this and more, including how to get energy from the water molecule to power a vehicle AND how to build robots that use only solar power (and never need a battery recharge!) Are you ready? Then let’s start with this video:


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Electromagnets Exercises

Sunday April 4, 2010

Let’s see how much you’ve picked up with these experiments and the reading – answer as best as you can. (No peeking at the answers until you’re done!) Just relax and see what jumps to mind when you read the question. You can also print these out and jot down your answers in your science notebook.


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Magnets Exercises

Sunday April 4, 2010

Let’s see how much you’ve picked up with these experiments and the reading – answer as best as you can. (No peeking at the answers until you’re done!) Just relax and see what jumps to mind when you read the question. You can also print these out and jot down your answers in your science notebook.


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Answers to Electromagnetism Exercises

Sunday April 4, 2010

Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!


Here’s printer-friendly versions of the exercises and answers for you to print out: Simply click here for printable questions and answers.


Answers:
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Answers to Magnets Exercises

Sunday April 4, 2010

Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!


Here’s printer-friendly versions of the exercises and answers for you to print out: Simply click here for printable questions and answers.


Answers:
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Galvanometers

Sunday April 4, 2010

Galvanometers are coils of wire connected to a battery. When current flows through the wire, it creates a magnetic field. Since the wire is bundled up, it multiplies this electromagnetic effect to create a simple electromagnet that you can detect with your compass.
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Eddy Currents and Magnetic Brakes

Sunday April 4, 2010

Eddy currents defy gravity and let you float a magnet in midair. Think of eddy currents as brakes for magnets. Roller coasters use them to slow down fast-moving cars on tracks and in free-fall elevator-type rides.


Here’s what you need to do this activity:


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