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Wind Vane

Before You Start...
A weather vane is also called a wind vane. It is a tool for measuring wind direction. It spins on a rod and points in the direction from which the wind comes.

The weather vane is one of the oldest weather tools. The part of the vane that turns into the wind is usually shaped like an arrow. The other end is wide so it will catch the smallest breeze. The breeze turns the arrow until it catches both sides of the wide end equally. The arrow always points into the wind. The arrow tells you the direction from which the wind is coming.

Materials
paper and pencil
scissors
cardboard
compass
plastic soft drink bottle
plastic drinking straw
shallow pan filled with rocks
felt marking pen
 

Procedure
What is a weather vane? When have you seen weather vanes? Write down your answers. Draw a picture of a weather vane.

With the scissors, carefully cut an arrow with a tab from the tag board, as shown. Remember that scissors are sharp, so handle them carefully. Bend the tab slightly so the arrow turns easily when you put it in one end of the straw. Put the other end of the straw in the bottle. Remove enough rocks from the pan to make room for the bottle. Pile the rocks back around the bottle so it won't be blown over. (See illustrations above.)

A compass always point north. Use your compass to find north, and then mark the four sides of the bottle E, W, N, and S with a felt pen.

Set your weather vane in a high place such as the top of a playhouse or a slide. Make sure it does not wobble or tilt, and that it catches the slightest breeze.

Watch your weather vane closely and then describe how it works. Test it on windy days and again when there is just a light breeze.

Background Information
A weather vane is a tool used to tell which direction the wind is coming from. Weather vanes are usually found on top of buildings so they will catch an open breeze. Look for them on top of barns, houses, weather stations, hardware stores, and other places that sell or use weather tools. The part of the vane that turns into the wind is usually shaped like an arrow. The other end is wide so it will catch the smallest breeze. Sometimes a metal rooster or other animal sits on top of the weather vane.

You have made a weather vane! If the wind is blowing from the south, the wind is usually warm. If the wind is blowing from the north, the wind is usually cooler.

Some weather vanes have directional strips underneath the arrow to make it easier to read. Your markings on the bottle do the same thing.

The breeze turns the arrow on the weather vane until it catches both sides of the wide equally. The arrow always points into the wind.

It is easier to see how the energy from the wind moves your weather vane if it is up high and in an open area. You might also want to experiment by putting it on the ground.

A weather vane is one of the oldest weather tools. It is still used today to measure the direction of the wind. Weather vanes can only measure wind direction a few yards (meters) off the ground. Large, helium-filled weather balloons are used to measure winds high above the earth's surface. The balloons move with the same speed and direction as the wind.

http://sln.fi.edu/tfi/units/energy/dixie.html
 

Pinwheel Wind Collector

Materials

a pin
a square piece of construction paper (about 8.5" x 8.5")
a sharpened pencil with an eraser
scissors

Procedure

Lay the square of paper flat on a table and draw a line diagonally from each corner to the opposite corner. Mark the center of the square where the two lines cross and punch a small hole through it with the pencil tip. Next, cut along each line stopping about an inch from the hole in the center of the square. Take the pin and punch a hole in the top left corner of each of the four flaps. (No two holes should be next to each other.) Pick up a flap at a punched corner and carefully curve it over toward the center hole, securing it with the pin. Repeat this for the other flaps. When all four flaps are held by the pin, carefully lift the paper without letting the flaps unfurl. Lay the pencil flat on a table and carefully push the point of the pin into the side of the eraser.

Now your pinwheel is complete and ready to go. Pick up the pinwheel near the pencil point and let it catch the wind. Your students should discover that the pinwheel only spins when the wind hits its center.

You now have a simple wind collector. The pinwheel is an example of a horizontal-axis active wind collector. It must be pointed into the wind in order to spin.

BLUE SKY EXPERIMENT

MATERIALS:

• flashlight
• 2-liter pop bottle
• milk
• water

PROCESS:

Fill the 2-liter bottle three-fourths full of water and prop up the flashlight, so it will shine through the bottle from the side.

Add a teaspoon of milk to the water.

Put the cap on the bottle and shake to mix up the water and milk.

What do you see? Keep adding milk until you start to see a blue light that is scattered to your eyes from the mixture.

Once you see the blue light, add more milk to the mixture until you see more of an orange or red light.

EXPLANATION:

Just like in the atmosphere, the mixture scatters more of the blue wavelength than any other color. That’s why the sky is blue! At sunrise or at sunset, there is even more scattering taking place due to the angle of the sun. This causes the reds and oranges to scatter into our atmosphere. That’s why our sunsets and sunrises are so colorful!

EXAMINING COLORS

MATERIALS:

• red, blue and yellow food color (primary colors)
• 1 cup of milk
• dish soap
• shallow and flat bowl or container

PROCESS:

Pour 1 cup of milk into the bowl.

Add 3 drops of red food color to one edge of the bowl.

Add 3 drops of blue food color 1/3 of the way away.

Add 3 drops of the yellow food color 1/3 of the way away.

Don't mix of jiggle the bowl.

Squeeze a drop of the dish soap in the center of the bowl.

Watch what happens!

EXPLANATION:

The dish soap does not mix with the milk. Instead, it floats on top and spreads over the surface. As it spreads, it grabs the food color of the primary colors you dropped into it. Where the color meet, the combine and form new colors. We call these colors, secondary colors!

Red + Yellow = Orange

Blue + Red = Purple

Yellow + Blue = Green

INDOOR RAINBOW

MATERIALS:

• glass jar or a large drinking glass
• small mirror
• flashlight
• dark room with white walls

PROCESS:

Fill the jar or glass with water.

Place the mirror inside the water filled jar or glass.

Tilt the mirror slightly upward.

In a very dark room with white walls, shine the flashlight onto the mirror.

A rainbow will appear! (Note: If no rainbow appears at first, just change the angle of the light from the flashlight or change the angle of the mirror.)

EXPLANATION:

The mirror reflects light that passes back through the water, traveling at an angle. The water bends, or refracts, the light. As the light bends, it separates into the colors of the rainbow...red, orange, yellow, green, blue, indigo and violet.

CLOUD IN A BOTTLE

MATERIALS:

• 2-liter clear plastic pop bottle
• matches (children will need adult assistance to light matches)
• warm water

PROCESS:

Fill the clear plastic 2-liter bottle one-third full of warm water and place the cap on. As warm water evaporates, it adds water vapor to the air inside the bottle. This is the first ingredient to make a cloud.

Squeeze and release the bottle and observe what happens. You’ll notice that nothing happens. Why? The squeeze represents the warming that occurs in the atmosphere. The release represents the cooling that occurs in the atmosphere. If the inside of the bottle becomes cover with condensation or water droplets, just shake the bottle to get rid of them.

Take the cap off the bottle. Carefully light a match and hold the match near the opening of the bottle.

Then drop the match in the bottle and quickly put on the cap, trapping the smoke inside. Dust, smoke or other particles in the air is the second ingredient to make a cloud.

Once again, slowly squeeze the bottle hard and release. What happens? A cloud appears when you release and disappears when you squeeze. The third ingredient in clouds is a drop in air pressure.

EXPLANATION:

Water vapor, water in its invisible gaseous state, can be made to condense into the form of small cloud droplets. By adding particles such as the smoke enhances the process of water condensation and by squeezing the bottle causes the air pressure to drop. This creates a cloud!

Above four  experiments from: http://www.weatherwizkids.com/optical_illusions.htm