Science Fun:
How to Make a Homemade Thermometer
This project is really interesting and fun; however, it does need close adult supervision to complete it. This is a really fun addition to a homemade weather station!

Project Supplies:

Tap water
Rubbing alcohol (do not drink this)
Clear, narrow-necked plastic bottle (11-ounce water bottles work well)
Food coloring
Clear plastic drinking straw
Modeling clay

Project Directions:

1. Pour equal parts of tap water and rubbing alcohol into the bottle, filling about 1/8 to a 1/4 of the bottle.

2. Add a couple of drops of food coloring and mix.

3. Put the straw in the bottle, (DO NOT DRINK MIXTURE) but don't let the straw touch the bottom.

4. Use the modeling clay to seal the neck of the bottle, so the straw stays in place.

5. Now hold your hands on the bottle and watch what happens to the mixture in the bottle.

Project Explanations:

Just like any thermometer, the mixture expands when it is warmed. This makes the liquid no longer fit in the bottom of the bottle. As the alcohol expands the colored mixture moves up through the straw. If the bottle were to get very hot, the liquid would have come through the top of the straw.

You can watch the thermometer and see how the liquid changes throughout the day. What happens if your thermometer is in shadow or in sunlight? What happens when it gets colder? How does wind affect the thermometer?

In order to accurately read the temperature, you will need to buy a real thermometer that is carefully calibrated for temperature changes. This one is to see how a thermometer works -- just for fun.

Important Safety Note: After you're done with your thermometer, dispose of the liquid properly and rinse the bottle well. Cut it in half, or have a parent cut it in half, so the bottle can't be reused. The used bottle could have some left over alcohol in it, and you don't want anyone to reuse the bottle for drinking water.
Balloon Jet
This is a very simple rocket that demonstrates the most basic principle of rocketry: how pressurized gas creates thrust.
Materials
* String or fishing line * Straw * Tape * Balloon
What To Do 1. Tie one end of the string to a chair or doorknob across the room from you. 2. Blow up a round balloon a couple of times to get it stretched out. Then blow it up and pinch the end closed so no air can escape. Holding the inflated balloon closed, have an assistant help you tape a straw to it. 3. Thread the straw onto the free end of the string. Hold the string taut and then let go of the balloon.
What's Happening?
The air in the balloon is gas under pressure. The air pushes against the balloon, causing it to expand, but the balloon is also pushing back on the air. When gas or liquid is under pressure, it tries to escape. In the case of the balloon, it escapes out the open end. In a rocket, it escapes through an opening called a nozzle. As the gas escapes, it creates the thrust that propels your rocket forward (or a real rocket upward). This is because of one of Newton's Laws of Motion: for every action, like gas escaping from a rocket in one direction, there is an equal and opposite reaction, like the rocket moving in the other direction.
To do some more experimenting with your simple balloon rocket, test how far it will go with different amounts of air: full, half full, a quarter full, etc. (You can measure the actual volume of air inside the balloon by using a flexible tape measure to measure the circumference of the balloon. Use the circumference to find the diameter: just divide the circumference by π (3.14). Next find the volume with the following equation: Volume = 1/6π (Diameter) ³. After several tests, make a graph to show the relationship between the balloon's volume and the distance it travels.)
Another experiment idea is to see if you can design a way to control the flow of air through the "nozzle" —if the air comes out too slowly there won't be enough force to move the rocket forward, but if it escapes too quickly the rocket won't go very far. Finally, try using different types of string for your balloon rocket to travel along. Do you think the balloon will travel the same distance along yarn as along fishing line? Why or why not? (Hint: friction!)
Rockets heading to outer space need a lot of energy to escape the pull of the earth's gravity! Instead of a single rocket trying to do all the work, aerospace engineers build rockets that perform in stages. As the first rocket stage burns itself out, another one takes over. Try this NASA project to make a two-stage balloon rocket. newtonian Demonstrator $13.95
Item# MC-NEWTDEM In Stock
This popular device, called a Newtonian Demonstrator or Newton's Cradle, is used to study Newton's 3rd Law of Motion: for every force there is an equal and opposite force. Lift and drop a ball on one end and the ball on the other end responds with an opposite motion. Drop two balls on one end and two balls respond on the other end. This Newtonian Demonstrator features 20 mm diameter chrome-plated steel balls suspended on nylon string from a steel frame mounted to a durable wood base. Operating instructions and theory are included. The overall size is 12 cm (4.8")
Rockets & Flight
In this issue you can make your own flying machine using an index card and a straw, and read about all sorts of things that fly including spaceships!
Rockets & Flight Science Projects
Make a Paper Flying Machine
Make a kind of glider or flying machine that will go farther even than a paper airplane! To make your paper and plastic flying machine soar through the air you will need to give it thrust by tossing it with your hand, just like a rocket needs thrust to take off from the ground.
What You Will Need: * 1 regular plastic straw * 3x5" index card (or cardstock cut to size) * Scissors * Tape
What To Do: 1. Cut the index card into three strips that are 1" wide and 5" long. (Get an adult to help you.) 2. Overlap the edges of two of the strips by about one inch, and tape them together. Now you have one long strip. Bring the two edges of the long strip together, overlap them, and tape them together to make a loop. 3. Make a smaller loop with the last index card strip by overlapping the edge and taping together. 4. Set the straw inside of the small loop, so the end of the straw sticks just outside of the end of the paper loop. Tape the straw to the inside of the small loop. 5. Tape the other end of the straw to the inside of the large paper loop. Make sure that the straw is set evenly inside of each loop, not to one side or the other, so your flying machine will be balanced. Also, be sure that the openings of the straw are not taped shut. 6. To fly your glider, hold it with your thumb and index finger, and toss it in the air at a slight upwards angle.
What Happened?
Your glider was able to fly when you pushed it forward. Force is the word scientists use to talk about different kinds of pushes and pulls. Different forces create motion (anything that is moving has motion). Flight is a kind of motion. Your glider flew a long way, didn't it? All of the thinnest parts of the machine are the ones that needed to be pushed through the air. Air is light, but it still has weight. You had to use force to make your flying machine cut through the air, and because of the way you made it, it worked really well! A little bit of force made the glider go a long ways. What do you think you could do to make your flying machine even better? Could you make it lighter by using a shorter straw? Try it out.
Rocket Pennies
What To Do: 1. Put an empty plastic bottle (from water or soda) in the freezer, with the lid off. 2. Take the bottle out of the freezer after one hour. Get the penny wet and slide it around the top of the bottle, until it sticks there. Put the penny and the bottle back in the freezer for one more hour. 3. Take the bottle out of the freezer, and hold it in both of your hands being careful not to squeeze the bottle too tightly. Your hands should start to warm up the bottle. 4. After a few minutes of holding the bottle in your hands, the penny should pop up into the air!
What Happened?
When air warms up, it takes up more room (expands). When the air inside the bottle got warmer, it expanded - but it had nowhere to go! So, the penny was pushed out of the way by the air. The way a rocket works is very similar to this. Instead of being powered by hot air, a rocket is powered by expanding gas. In a rocket engine, two different kinds of fuels are heated and mixed together to make a lot of gas, and it expands very quickly. Just like in this experiment, the pressurized gas wants to escape. In a rocket, it's directed out through a nozzle and hits the ground with enough force to push the rocket up into the air!
Fun Facts * The footprints and tire tracks that have been left by astronauts on the moon will stay like that forever, because there is no wind there to blow them away! * If you were in space standing right next to a friend, you could shout at them and they still wouldn't hear you. * To lift an 85 pound person off of the ground it would take about 3,000 helium balloons!
Silly Science * Did you hear the one about the spaceship? * It was out of this world! * What only works when it's fired? * A rocket. * What is the best material for a kite? * Fly pape