## Model Steam Engine

An engine is a machine that turns energy into motion.  Here we give instructions on how to make your own model steam engine from inexpensive materials. Read on for detailed instructions on building the steam engine and on how steam engines work. How A Steam Engine Works A steam engine works by heating water in a pipe, turning the water to steam.  As the steam heats the gases expand creating pressure.  The pressure can be used to move parts. In this diagram below you can see that water is run through pipes above a very hot chamber.  The water is turned to steam as it heats then the steam is heated even further as it runs through more pipes.  Finally the steam escapes with great force out a pipe (number 5) where it is used to create motion for an engine. A steam engine is an external combustion engine.  This … click to read more

## Lava Lamp Density

You can make your own lava lamp to watch as carbon dioxide gas is released, creating a cool and colorful science show.  We’ll talk about density as we go along with the experiment. You’ll need: water a clear bottle or jar (we used a pretty wide jar, but narrow ones work even better as the bubbles are more visible against the outside walls) vegetable oil food coloring Alka-seltzer tablets And here’s what you do: Start by filling the bottle or jar about 1/4 full of water.  Add 12-15 drops of food coloring to it. Then fill the rest of of it up with vegetable oil.  Give the oil and water a few minutes to separate.  You’ll be able to see the two distinct layers, and because the water is more dense than the oil it sinks to the bottom. Drop Alka-Seltzer tablets in. If you want, you can cut an … click to read more

## Velocity

In this experiment you can actually see velocity at work.  Velocity is speed plus direction.  A car traveling in a straight line at a constant speed has a constant velocity, but if the car turns around a curve in the road then the velocity changes, even if the speed stays the same.  Or a car that is changing in speed, even if it continues in the same direction, has a changing velocity.  A car with both a changing speed and changing direction also has a change in velocity.  A change in velocity is an acceleration, even if only the direction changes and not the speed. Velocity Experiment This is an apparatus that will allow you to see changes in velocity. You need a: 2 liter bottle cork push pin string water Fill the bottle with water. Attach a string to the cork with a push pin then tie the other … click to read more

## How To Make A Hot Air Balloon

Hot air rises.  If you trap the hot air, you can get it to lift a balloon into the air.  Here is how to make a tissue paper hot air balloon. Hot Air Balloon Supplies First, you’ll need to gather your supplies.  You need: paper clips tissue paper school glue thin wire wire cutters scrap of light cotton fabric wax & matches or lighter scissors pencil poster board ruler Cut Out the Balloon Shape Layer four pieces of tissue paper on top of one another, fold them all in half and use paper clips to secure the pieces together on the folded side.  Then cut a balloon shape similar to the one below through all layers of tissue paper.  It doesn’t matter if the shape is just so, it just needs to be a general balloon shape and as large as your paper will allow.  At the bottom you should … click to read more

## PVC Rocket

All rockets are powered by explosions.  All explosions are rapidly expanding gases.  Usually they’re expanding because they’re burning, but not always. In the PVC rocket launcher the propellant is burning hairspray. The Science Behind the PVC Rocket In the rocket we built, the hair spray inside the tube is set on fire.  Hairspray is tiny particles suspended in the air, it is in aerosol form.  This means each little particle is mixed with lots of air.  And each little particle is also very inflammable, it will burn with the slightest provocation.  When the hairspray burns the chemicals in the hairspray, which usually includes some form of alcohol, mixes with oxygen and forms carbon dioxide gas.  The carbon dioxide gas formed is in much greater concentration than that of the surrounding air.  That means the pressure inside the launching tube is much greater than the pressure outside.  The easiest way for … click to read more

## Heat Conduction Experiment

Heat conduction is when heat is transferred through molecular agitation without any movement of the object as a whole.  Essentially, as a molecule heats up, it moves and shakes quickly, then moves the other nearby molecules, which move and shake in turn.  Bit by bit, heat is transferred through those movin’, shakin’ molecules in a chain reaction.  This may seem complicated, but it’s simple to demonstrate with this heat conduction experiment. Start by putting a pot of water on the hot stove.  Once the water is good and hot (boiling or near boiling), carefully place 3 different spoons in the pot – one metal, one plastic or rubber, and one wooden spoon. The next step is to make a prediction about what will happen of you place a little pat of butter on each of the spoons.  Have the kids write down their predictions. Here is a scientific method experiment … click to read more

## Simple Light Refraction Experiment

Light refraction is the bending of light when it hits a substance of a different density.  We’ll show you a simple light refraction experiment you can do at home to demonstrate this quality of light. When light passes from air to water it is refracted in the water because the water is more dense than the air.  The change in density means the light slows down and slowing down makes it change direction.  When the light changes direction it makes objects in water appear to be in a different place than they actually are.  If you ever dove after a ring in the bottom of a pool you’ve observed this. Light Refraction Experiment All you need is a bowl, with opaque (not see through) sides, a coin, and water. Place the coin in the bottom of the bowl. Back up until you’re about two feet from the bowl, then bend … click to read more

## Optical Illusions

The eye is made up of two different types of light receptors called cones and rods.  Cones are necessary for color vision and to see well in bright light.  Rods are necessary for seeing in low light.  The two optical illusions experiments we’re about to show you fool the light receptors in the eye so the eye sees something that is not actually there. Benham Top The first is called a Benham Top.  In 1894 C.E. Benham created this toy he called the “Artificial Spectrum Top”.  As the black and white disk spins the eye picks up colors. First print out the Optical Illusion Disks. Get an old CD and a penny.  Heat the penny in a pan on the stove (or over a bunsen burner or torch) until it is very hot.  Using pliers grasp the penny and slide it into the hole of the CD at a 90 degree … click to read more

## Marble Roller Coaster Physics

Marble roller coaster physics teaches kids about some important basic principles including Newton’s Laws.  You need pipe insulation (a few bucks at any home improvement store), duct tape, and marbles.  We used about 3 lengths of the pipe insulation and had more than enough. First, start by cutting your pipe insulation in half the long way.  Scissors or an exacto knife work well. Don’t tell the kids how to do it.  Just provide various challenges.  For example, I challenged them to create a roller coaster with at least one loop and one turn that the marble got safely through. They had to figure out how much rise (or FALL in our case) they needed over run to make the marble complete the loop. We used books, baskets, duct tape – anything we had lying around that would help us craft a variety of cool tracks. Some things to try: 1. … click to read more

## Experiments With Electricity

There are lots of cool experiments with electricity that you can do at home with your kids. Materials To perform electricity experiments with kids from 1st through 8th grade you need these materials: electrical wire: a couple of feet from your local hardware store or you can buy the type with alligator clips from a science supplier.  If you want enough for each child, you’ll need one set of alligator clips per kid or 1 foot of plain old wire per kid. D batteries: one per child, at least flashlight bulb: one per child electrical tape: to hold the wire on to the other components Multimeter: measures voltage and resistance, one to share.  For larger groups you’ll need several, one per four kids. Electrode Set: conducts electricity, useful for passing electricity through liquids or for making the potato battery below.  One set per child. Optional, but nice to have: Battery holder: easy to attach the alligator clips, keeps things in … click to read more