That toy that can walk down the stairs all by itself has some pretty interesting science behind it. How does that thing work anyway? Take a look at these websites and videos to see the amazing slinky at work. And then go try some of this stuff – does your slinky follow the same scientific rules?
Nitro Joe will be appearing in several library branches throughout the summer. During his show, Joe will show you just how real air really is. Nitro Joe will use air pressure to crush objects and move things around. Bernoulli’s Principle will be demonstrated by making toilet paper fly and by creating Tornado Donuts. Nitro Joe’s Schedule
Keywords that promise a good time:
Even though air seems like nothing, it really is something. Gases like air, even though they are not visible to our eyes, are made up of molecules just like solid objects. These molecules are pulled toward the earth by gravity.
Earth is surrounded by a layer of air that is heavy. That layer of air exerts pressure on the surface of the earth, a lot of pressure. Our bodies are used to it so it doesn’t bother us. In fact, we are so used to it that what bothers us is when the air pressure is gone.
The higher you go in the atmosphere, the less air pressurethere is because the “thickness” of the air is less the higher you go. That’s why airplanes have “pressurized” cabins. We can’t survive in too littleair pressure.
Here are some websites and books that will help you understand air pressure:
Air Pressure – The force that air exerts due to it’s weight. Even though air seems like nothing, it really is something. Gases like air, even though they are not visible to our eyes, are made up of molecules just like solid objects.
Fill each glass with water. Put several drops of food coloring in each glass – one color in each. You will have one cup that is red, one that is blue, one that is green and one that is yellow. Now take the straw and put one end of it in the red glass so that one inch of the straw is covered with water. Put your thumb over the other end of the straw and pull the straw out of the water. See how the red water is still in the straw?
Now, with your thumb still covering one end of the straw, submerge the red end of the straw into the blue cup until two inches of the straw is covered with blue water. Slowly lift your thumb and then put it back on the end of the straw again. Draw the straw out. What happens to the blue and red water in the straw?
Now add 1 teaspoon of salt to the red glass, 2 teaspoons of salt to the blue glass, three teaspoons to the green glass and 4 teaspoons to the yellow glass. Repeat the experiment until you have four inches of water in the straw. What happens to the four colors? Did fresh water behave differently than salt water?
When you added salt to the water you increased the density of the water. Density is how close together the molecules of a substance are or how much mass a substance has in a given space. If you have one cup of jelly beans and one cup of marshmallows…the jelly beans have more mass…there is more “stuff” compacted into the cup. The marshmallows are mostly air. If you put each of those cups in a microwave to melt…the sugar and water that makes up the jelly beans would almost fill the cup to the top. The sugar and water that makes up the marshmallows would only fill the cup a little bit because marshmallows have less mass, they are mostly made of air. A cup of salt water has more density than a cup of plain water. The more salt you add to a cup of water, the more density it has.
Each of the four colors of salt water have different amounts of salt. The colors with more density are heavier and will sink to the bottom when all four colors are mixed together.
Here are some websites and books that will help you understand density:
Density – How closely packed together the molecules of a substance are. Mass - How much matter fits in a given space. Matter- Stuff Weight - A measure of the force of gravity on an object. Materials with more density weigh more. Volume – How much space a substance takes up. *****The confusing relationship between weight and mass: On earth, a bowling ball can weigh about 10 pounds. If you take that same bowling ball to the moon it will weigh much less because the graviational pull of the moon is less than the gravitational pull on the earth. Weight is a measure of gravitational pull. So the weight of the bowling ball, or anything else, changes depending on where you weigh it. The mass of the bowling bowl does not change no matter where it is. The bowling ball has the same amount of mass on earth as it does on the moon or anywhere else you take it.
An insulatoris a substance that prevents the transfer of heator cold. Your winter hat is an insulator. It keeps the cold in the winter air from making your head cold. It blocks the transfer of cold from the air to you. It also blocks the transfer of heat from your head to the air.
Here is an experiment that will show you how different materials make better insulators than others.
What You Need:
3 Identical Coffee Mugs
4 Rubber Bands
Cotten Fabric (t-shirt – check the label)
Wrap the paper towel around the outside of one mug and secure it with a rubber band. Do the same with the other three mugs using alumninum foil, cotton and the wool sock.
Fill a pitcher with very hot tap water. Be careful! Take the temperature of the water and write the temperature down.
Fill each cup to the top with the hot tap water. Wait five minutes and take the temperature of the water in each cup. Make a chart to keep track of each cup’s temperature. Record each temperature after 5 minutes, 10 minutes and 15 minutes. What happens to the temperature of the water in each cup?
Here are some websites and books that will help you understand heat and insulators:
Words to Know: Insulator - A reduction of heat transfer between objects. Insulators keep cool things cool and warm things warm – like the thermos in your lunch box or the blubber on marine mammals. Heat - A high temperature. Temperature – The level of heat present in a substance or of an object or person. Temperature is measured on a thermometer and expressed in number of degrees. Temperature can also be determined by using the sense of touch. Human skin is sensitive to changes in temperature.