Tuesday, June 30, 2009

30 Second Science - Bernoulli's Principle

My children have seen demonstrations of Bernoulli's principle at children's museums here and there, but I like to repeat a few basic experiments at home to keep them from forgetting about it, as time passes. Simply stated (and I do mean simply), Bernoulli's principle is that moving air creates low pressure. It is the principle behind the idea of lift for airplanes, and gliding birds.

It can be demonstrated very easily with a hair dryer, and a light weight ball, such as a ping pong ball (though balloons or other light balls, like those plastic ball pit balls, work too). Just point the hair dryer up, turn it on using the coolest setting, and place the ball gently into the stream of air.

You can place more than one ball at a time into the air.

Because the air flow is creating lower pressure than the air outside of the flow, the higher pressure will push the ball back into the air stream if it starts to move to the side. You can tilt the hair dryer from side to side, and the ball will remain in the air stream, until you tilt enough, that the force of gravity overcomes the force of lift.

If you do not have a blow dryer, you can use a drinking straw and lung power.

There is also a kid friendly explanation of the principle, and a printable paper airplane template, for further demonstrations, at www.fatlion.com/science/paperairplanes.html.

It's great to be a homeschooler.

Monday, June 29, 2009

Make A Toy Hovercraft

Why not recycle a few of those scratched DVDs, or Cd's you pulled out of a cereal box, and make a great science toy at the same time?

For this project you need:

  • a CD or DVD that can be sacrificed to the project
  • the top off of a water bottle, pancake syrup, or dish soap bottle (the kind that you pull up to open, and push down to close)
  • a balloon (the bigger the better, but any size will do in a pinch)
  • hot glue, or crazy glue

The steps for construction are extremely simple.
Glue the bottle top over the hole of the CD. It is important to make an airtight seal between the CD, and the edge of the bottle top, but do not block the hole in the CD.

After the glue dries, place the balloon on the bottle top, covering the entire thing.

With the bottle top open, blow up the balloon by blowing through the CD. When the balloon is full of air, close the bottle top (this can be a little tricky, but it is possible). Place the hovercraft on a smooth surface, and open the bottle top.

A little push demonstrates Newton's first law of motion (see http://gbhsweb.glenbrook225.org/gbs/science/phys/class/newtlaws/u2l1a.html for a kid friendly explanation of Newton's laws, or have them watch The Magic School Bus Plays Ball).
It's great to be a homeschooler.

Sunday, June 28, 2009

Road Trip - On The Lewis And Clark Trail

Traveler's Rest just east of Lolo, Mt is the only archaeologically verified campsite of the Corp of Discovery along the entire 8,000 miles of the trail. Once, a month throughout the summer and fall, they hold "Discover the Seasons" events at the site. Yesterday's event highlighted the food of the trail, and of the local indians through the years.

We weren't sure what to expect when we saw the visitor center, a yurt in the middle of what appears to be an unused field at the edge of the highway, and nearby huddle of makeshift tents and tepees, that made up the event. However, the volunteers manning the tents were friendly, knowledgeable, and generous with their time, and samples of food, and fun.

We were treated to a fire making demonstration, using flint found in the Philipsburg area, with cottonwood fluff for tender (cottonwood is highly incendiary - making for a good show). Then we were given a sampling of dried fruits and meats, hardtack, salt pork, and some very interesting wild wheat and berry cookies. There was a flintlock demonstration, and each of the children received a deerskin bracelet, braided with a mystery braid, while they watched.

Despite the somewhat humble look of the place, we were on information overload within an hour. So, to clear our heads a bit, we continued west on the highway toward Lolo Pass, following the Lewis and Clark trail. As it turns out we were also retracing (only backwards) the Nez Perce trail. They used this route to enter the Bitterroot Valley, not long before their battle with US troops in the Big Hole area (that's a road trip for another day).

At the top of the pass, we stopped off at the rest stop, and wandered into the visitor center, only to discover another small museum, packed with information and tactile displays. There was more information about Lewis and Clark, the Nez Perce Indians, and local geology. Outside was a self guided tour of the two trails along beautifully maintained walking trails. And, let's not forget that we were in the Rocky Mountains - the scenery was breathtaking.

We turned around just beyond the pass. Like the Nez Perce we snuck quietly by Fort Fizzle (another historic site along the highway), and reentered the Bitterroot without incident. What had started out to be a leisurely Saturday drive, had turned into a busy educational outing - and a lieserly Saturday drive.

It's great to be a homeschooler.

Saturday, June 27, 2009

Around the World in Eighty Days - Unit Study Day 5: Building a Put Put Boat

As we picked up the pace of our reading (we're hoping to complete Around the World in Eighty Days this weekend), we embarked on one last project, that proved to be just about as difficult as making a trip around the world ourselves. Since Phileas Fogg does the majority of his travel by steam train or steam ship (there's no adventure with a hot air balloon in Verne's novel - at least not this one), it seemed only natural to do a little study of steam engines.

The Mid-Continent Train Museum has a pretty good explanation for kids, of how a steam locomotive works. They also have coloring pages, printable crossword puzzles, and a quiz dealing with steam trains at www.midcontinent.org/kids/kids.html. I'm hoping later this summer to hook up with a steam train ride somewhere here in Montana, but it's a big state, and a short summer, so we'll see.

In the meantime, I decided we should try building a toy version of a steam ship. These are often called pop pop, or put put boats. Simple ones can be purchased for under $10.00, but it costs even less (and you lean even more) if you make one yourself (at least that was my thinking as we started our project). For the do-it-yourselfer, there are a couple of different options.

The simple version, used by the Boy Scouts, calls for some flexible copper tubing (see www.sci-toys.com/scitoys/scitoys/thermo/thermo.html#boat). There's a more complicated version at http://www.sciencetoymaker.org/, which uses only drinking straws and a pop can for the engine, and a milk or juice carton for the boat. I know that sounds simple, but there are more than twenty steps involved, and you end up using both a hot glue gun, and epoxy before you're finished.

Still, armed with the promise from The Science Toy Maker, that anyone who could follow simple instructions, could complete the project - we steamed ahead. If you want to make one of these yourself, check out the website for complete instructions, but by way of overview, let me tell the project involves...

cutting up a tin can...

...cutting it and folding it according to a printable template...

...shaping it with straws, which eventually get epoxied in...

...making it air tight with epoxy. Testing for leaks (and then fixing them with more epoxy)...

...building an angle tool with another printable template, to form and hot glue the engine around...

...cutting apart a milk or juice carton...

...stapling, sanding, and hot gluing the boat together...

...hot gluing the engine into place...

...making a candle holder out of tinfoil...

...checking for leaks (ours leaked like a sieve), and adding more hot glue...

...testing the boat.

Our boat did work, and did make the wonderful little put put noise, as promised. The only drawback - other than the long hours of building it, the dangerous epoxy fumes, dealing with sharp sided aluminum, and the burn dangers of hot glue, was that the boat only ran for about five seconds (okay, maybe it was 30 seconds) before the tiny candle was used up, and with no heat to create steam, the boat putted to a halt. Not exactly earth shattering! My advice is watch the Toy Maker's video, and explanation of how the boats are powered, and then shell out the $10 or so, to buy one with a longer lasting oil lamp already in place.

Or, scrap the project entirely, and settle in for a nice game of Whist. Keep the cut up pop can though, it makes a really good object lesson for figuring the surface area of a cylinder.

It's great to be a homeschooler.

Friday, June 26, 2009

Around the World in Eighty Days - Unit Study Day 4

I am pretty certain that we are not going to make this more than a 5 or 6 day unit study, which means that we have some heavy reading ahead of us, since we only read two chapters yesterday, taking us through chapter 14. As Phileas Fogg detoured to save Aouda, we detoured to http://www.snaithprimary.eriding.net/, to learn a little more about the country of India.

Getting back on track, we focused on learning a bit more about Asia as a whole, and played a mapping game at www.kidsgeo.com/geography-games/asia-map-game.php. This led nicely into a mapping project to demonstrate the difficulty of turning a round globe into a flat map.

We started out with a flat map (I know that's backwards to what I just said, but hang in there). After gluing it to a cereal box to make it a little stronger, we drew an orange peal design over the top of the map.

Then we cut out the orange peal.

Using a thumbtack to make holes in the tops of the "petals", and then hold them together, we formed our map into a globe (almost). It was quite clear that we left a good deal of the map behind in the process.

Moving the other way through the project, we blew up a balloon, and drew some pictures on it. We started out with lines representing the equator and the prime meridian, and then added one picture in each of the four sections of hemisphere.

We let the air out of the balloon, cut it open, and attempted to stretch it out into a rectangle. The effect was good, but as you can see from the pictures, we used a washable marker that didn't dry on the surface of the balloon, so things got a little messy.

We marked our story map through Calcutta, and noted Phileas Fogg's arrival in that city on October 25th on our log. Then, we decided instead of filling in our vocabulary sheets, we would begin watching the 1950's movie version of Around the World in 80 Days starring David Niven. Since that is a three hour movie, it pretty much finished off our day. But, with David Niven as our guide, we finished it off with a good deal of British pomp and dignity.

It's great to be a homeschooler.

Thursday, June 25, 2009

Around the World in Eighty Days - Unit Study Day 3

We continued to follow Phileas Fogg through chapters 9-11 of Around the World in Eighty Days by Jules Verne, marking his progress through India on our map, and making note of the date he passed through Bombay, on our log sheet. The rest of our study included;

Vocabulary: caprice, boisterous, propitiate, indefatigably, amiable, minaret, fakir, pagoda, cistern, despotic, dominion, rajah, insurrection, cumbrous, deign, grottoes, promenade, crestfallen, viaduct, verdant, rite, reverie, vagabond, maledictions, obstinately, conveyance, zebu, avarice, howdah.

Project: To demonstrate the concentration of population within certain areas (some of which Mr. Fogg experiences as he makes his journey), we printed off a list of some of the largest cities in the world, listed in order of population from www.worldatlas.com/citypops.htm . Then we printed an outline map of the continents, and glued it to a piece of cereal box to make it sturdy. Using our city list, an atlas, and a thumbtack, we made holes in the map for each of the 25 most populated cities on our list.

When you hold the map up to a window, the population centers shine like cities at night. Obviously, the more large cities you include the better the effect will be.

We compared our map to the picture of the world at night, that was so popular in the email for a while. Just google "the world at night", and several aerial images will pop up. This led us to an interesting discussion of whether you could see the whole world at one time from space? And, if you could, would it all be dark at the same time? And, if it was all dark at the same time, what would be the chances of finding a completely cloudless night over the entire surface of the globe?

Just for Fun; We watched the latest movie version of Around the World in Eighty Days, with Jackie Chan. It has almost nothing to do with the original novel, but it does seem to aim at capturing the adventurous spirit of invention found in the other works of Jules Verne.

It's great to be a homeschooler.

Wednesday, June 24, 2009

Around the World in Eighty Days - Unit Study Day 2

I would have loved to have made rhubarb and gooseberry tarts for the kids, to start out our lesson today (it's one of the things Phileas Fogg had for breakfast on the day he started his journey), but there is not a canned gooseberry to be had on the western side of Montana. Gooseberries do grow well in Montana, but will not be ripe for a couple of months. So, while we did receive a very nice invitation to pick as many as we like on the property of one helpful store clerk, that will have to wait until they are in season. Instead, I'll break down our study up to today, below.

Read chapters 4-8 in Around the World in Eighty Days by Jules Vern.

Vocabulary - conscientiously, chary, susceptible, ensconced, stupefaction, aberration, espoused, minutely, plied, quay, scrutinized, panorama, importunate, visaed, indispensable, rogue, inscribe, itinerary, stipulated, wont, volubly, fob, defiant, impenetrable, cogitating, and equanimity.
Again, you can find worksheets to go with these words at www.lessontutor.com/ees80printPT1.html.

Math - Create a chart to match Phileas Fogg's hoped for time schedule against his actual time schedule, as he moves through the story(something like the log Mr. Fogg keeps himself).

Take a moment to discuss world time zones. There is an excellent, kid friendly, site for this at www.time-for-time.com/zonesworld.htm.

Geography - Trace out Fogg's route from London to Suez on a world map. We used the Around the World in 80 Day's map from www.wikimediafoundation.org/wiki/File:Around_the_World_in_Eighty_Days_map.png.

And, as we listed Fogg's stops on our chart above, we added country information to the cities (this gave us a chance to discuss changes that have been made to the name's of cities such as Bombay - which is now Mombai, as well).

Project - World cookies (just to set the mood). Instructions for these can be found at www.chiccookiekits.blogspot.com/2009/04/sweet-earth.html, or you can just figure it out from the pictures below. The idea is to end up with a cookie that looks like the world from outer space. I put the frosting on, and let the kids swirl it for effect.

We also started watching Michael Palin: Around The World in 80 Days, a travel series put out by the BBC. It has some very good shots of the Suez Canal, and gives a modern take on the problems of world travel.

Finally, this would probably be a good time for some story starters such as, "What would I pack for a trip around the world?" or "How would we go around the world today?" Quite frankly, I have given up on creative writing for now, because the children are far to busy playing Whist to be bothered.

It's great to be a homeschooler.