Blowin in the Wind

By Susan M. Frack and Scott Prickett

BACKROUND:

When air moves from one place to another it makes a wind. Winds can be created in several ways. Air can be pushed.. When you blow out a candle or turn on a fan you are pushing air. Changing temperatures also makes air move. Air that is warmed becomes lighter. The warm air rises up over the cold air. The rising warm air makes a wind. In the same way, air that is chilled becomes heavier. It sinks down. As it drops down it makes a wind. Also, air is moved from areas of high pressure to areas of low pressure. The air moving from high pressure to low pressure creates a wind by pushing the low pressure air out of the way so it can takes its place. The wind gauge allows you to make accurate measurements of wind speed.

MATERIALS:

  • collection of fans
  • poster board
  • long stick/broom handle
  • markers or crayons
  • 2-3ft. sections of plastic rain gutter (available at most home supply/lumber yards-cheaply!)
  • golf ball
  • ping-pong ball
  • 6 foam coups
  • tennis ball
  • picture of sailboat
  • picture of tornado and its destruction
  • 1\2 foam cup for each student
  • 1 paper clip per student
  • tape
  • small wading pool or large washtub
  • butter tubs with lids
  • three inch nails
  • foil pie pans
  • non-bendable plastic straws
  • gravel

OBJECTIVES:

  1. Tell how wind is created on earth: changes in temperatures and air pressure.
  2. List good and bad effects of the wind.
  3. Make a weather vane and practice using it for 2 weeks.
  4. Tell what a wind gauge/anemometer does and practice using it for 2 weeks.

MOTIVATIONAL SET:

Gather a group of different sized fans from hand-held Chinese fans to powerful box fans. Let the children experiment with the different speeds and amounts of “wind’ created by each one. As the teacher, you may feel most comfortable with turning the fans off and on rather than letting the students do it. Ask the students to compare their experience with the fans to what happens outside:

  • wind blows their hair/clothing
  • wind blows the dust/ leaves/etc.
  • wind blows trees/ grass/flags/etc.

Older students may even be able to relate wind to colder conditions--wind makes it feel cool/colder outside than if the wind is not blowing. Some students may relate wind to storms or weather changes. Some students may talk about a “big fan” somewhere that makes the wind--dispel this myth!! Tell the students they are going to discover why the wind blows in nature because there isn't any “big fan” anywhere to create the wind.

TEACHING STRATEGY:

Part I.

1. Go into the gym or out on the playground--any large sized open area. Draw/mark an enclosed circle on the ground with chalk or tape that is just large enough for all of your students to fit into with little room to spare. Students should fit shoulder to shoulder. Tell the students to imagine they are pieces/molecule of air on a cool morning. They are close together because they are chilly and want to keep each other warm.

2. Make a large sun and attach it to a broom handle. stand several feet from the group and slowly raise the “sun”. Ask the children to tell you what happens to “them” as the sun comes up--get warmer. Instruct them, that as the air molecules, they don’t like to be close to each other as they get warm because they get sticky, sweaty, and even a little smelly. They will want to move slowly away from each other but they can’t leave the circle. Ask them where they can go?--up is the choice. Have those children closest to the sun jump up and out of the circle first because they are the warmest. They should “fly” around to the back of the circle and wait to get back into the circle. Students who were behind the first group should move up to the sun and warm up. This should leave room at the back of the circle for the first group to move back “down” into the circle because they have cooled off now that they are away from the sun and want to be back by their air molecule friends to warm up again. Soon, you should have a giant, human convection current going. Students should start to realize that they are creating “wind” with this movement.

3. Lower the sun and ask the students to tell what will happen to them/air molecules--slow down move back into the circle. Have them move accordingly.

4. Return to the classroom and discuss what they have learned:

  • sun’s warmth makes air move up as it gets warmer
  • as the air cools, it moves downward.
  • This movement happens world wide.
Draw a series of pictures to help remember and tell the story.

5. Ask students to remember the sun and how it makes the air warm up and move. Then Ask”Does the wind always stop at night when there isn’t any sun?” Many students will know that the winds blows at night as well. Ask them to think of some reasons why it might blow at night. Make a list on the board or on poster paper. Accept most reasonable ideas.

6. Now set up a demonstration that will help the students understand . Have several students help with this. Set up 2 identical ramps as follows:

Rain Ramp

Have 1 student roll a golf ball down his ramp and the other student roll a ping-pong ball down his ramp. The golf ball will push the cups out of the way/knock them down while the ping-pong ball shouldn’t move the cups at all. Discuss what happened. Relate the balls to the wind--heavy wind will move things and lighter air/wind will not move things as much. Then have students try a tennis ball and a baseball--both will move the cups but the baseball will do more damage. Speculate with them about what would happen if they used a basketball or a bowling ball. Come to the conclusion that “heavy” air pushes “lighter” air out of the way and that heavier, stronger air does more work/damage than lighter air.

7. Go back to the list of reasons for night wind and evaluate/cross off reasons. Students would understand that warm surfaces could create night breezes as well as heavy/large masses of air pushing into an area.

Part II

Put up the picture of the sailboat and the picture of the tornado. Discuss the pictures and tell what the “wind” is doing in each picture. Start a list under each picture. Decide if the effects of the wind are good or bad. Add other examples of good and bad effects of wind to the lists. You may want to watch a movie about wind/ tornadoes/etc. at this point. Students should than write some wind poetry about the effects of the wind. Haiku or rhyming couplets would work easily.

Part III.

Fill a tub or small wading pool with 2-3 inches of water. Set a 3-speed fan on a stool or on the floor on 1 side of the pool. The fan should be level with the top of the pool. Have the students make sail boats as follows: Students can decorate their sails with markers. Also, be careful not to push the paper clip all the way through the cup or it won’t stay upright.

Sailboat

Get everyone’s boat in the water and turn on the fan on low. Boats should move about the pool nicely without waves. Adjust the fan if necessary. Increase the fans speed to medium and small waves should appear and the boats should all move to the opposite edge. Increase to high and the boats should begin to blow over. Turn off the fan and discuss what happened. “Fix” all the boats and get them back into the water. Turn on the fan and move it around the edge of the pool to see the effect of wind from different directions. Talk about the boats’ movements. Students should begin to get an idea of how important it is for a boat to know how strong the wind is and from what direction it is coming from. Make a list of other jobs/ people/ things that need to know the speed and direction of the wind: pilots, farmers. builders, golfers, etc.

Introduce the term wind vane as measuring tool to determine the wind’s direction. Show different wind vanes or pictures of them. Some students may have seen them at the farm or on TV, etc. Students then should make their own wind vanes. See Appendix A.

Show students the wind gauge and show how to use it. Let everyone practice using it.

Keep track of the wind speed and direction for 2 weeks.

ADDITIONAL ACTIVITIES:

  • Wind Sock-Appendix B
  • Wind Chill-Appendix C
  • Simple Anemometer-Appendix D

APPENDIX A: 

WIND VANE

OBJECTIVE: to make a device to show the direction the wind is blowing.

MATERIALS:

  • butter tub with lid
  • 3 inch nail
  • gravel
  • foil pie pan
  • non-bendable plastic straw
  • scissors
  • stapler

DIRECTIONS:

  1. Have your teacher poke the nail up through the center of the butter tube.
  2. Have the teacher cut a dime-sized hole in the exact center of the lid for the butter tub.
  3. Put the straw over the nail and fill the tub with gravel.
  4. Draw lines on and label the top of the tub like the picture below: (NOTE--you may need to teach the names of the directions on the compass if your students are unfamiliar with them)
  5. Carefully put the lid on the tub. The straw should go through the hole.
  6. Trace the wind vane arrow pattern on the bottom of the foil pie pan with a marker or pen and cut it out. Carefully staple the “X” in the middle of the wind vane arrow to the top of the straw.
  7. Take your wind vane outside and set it on a flat surface with the N facing north--the teacher will help you. As the wind blow, it will turn the wind van arrow. The arrow points into the wind. That gives you the name of the wind. For example. an ar row pointing to the north tells you it is a north wind.
  8. Sometimes the wind van will point between 2 directions. These directions have special names:
    • between north and east is northeast
    • between east and south is southeast
    • between south and west is southwest
    • between north and west is northwest

WIND VANE ARROW PATTERN:

You can change the design on the top if you wish. 

APPENDIX B: 

HANG OUT A WINDSOCK

OBJECTIVE: Some airports use a windsock to tell the airplanes the wind direction. This helps pilots take-off and land safely. Hang out a windsock of your own to help you pilot your paper airplanes!

MATERIALS:

  • an old nylon stocking at least 2 feet long
  • needle and thread
  • thin wire -- 15 inches long
  • twine or string
  • scissors
  • hammer and 1 inch nail
  • 1/2-3/4 inch dowel, 3 feet long
  • large coffee can with lid
  • gravel
  • permanent marker

WHAT TO DO:

  1. Form the wire into a circle and wrap the ends together to hold it in place.
  2. Fold the open edges of the stocking around the wire circle and sew it down.
  3. Cut 4, 12-inch pieces of string and attach them to the wire as shown below:
  4. Pound the nail into the top of the dowel so that only about 1/4 on an inch of the nail is showing. Tie the strings around the nail as shown below:
  5. Cut a hole in the center of the coffee can lid that is the same size as the dowel. Mark the top of the lid with the compass directions : N, S, E, W, NW, NE, SE, SW.
  6. Fill the can with gravel and put the top on. Put the dowel through the hole in the top and push it through the gravel to the bottom of the can.
  7. Set the can on the ground, facing the right direction. The open end of the wind sock will turn and face the direction that the wind is coming from.
APPENDIX C 

WINDCHILL FACTOR

A breeze on a warm day makes you feel comfortable. But a wind on a cold day makes you feel even colder!! This effect of the cold air and wind is called the “wind-chill factor”. The chart below ill let you determine the wind-chill factor. The number is based on the temperature and the wind speed in miles per hour. For example, if your thermometer reads 30 degrees F and your wind gauge reads 15 miles per hour, the wind-chill factor is 9 degrees F. BRRRRRRRR!!!!!!!!!

Wind-chill Factor Chart:

Wind-chill chart

 

APPENDIX D: 

SIMPLE ANEMOMETER

Find out HOW FAST the wind is blowing with this anemometer that you can make yourself.

MATERIALS:

  • 1 inch diameter wood dowel, 2 feet long
  • 2 ping pong balls
  • sharp knife
  • 2 thin pieces of wood, each 20 inches long
  • 4 small nails or tacks
  • 2, 2-inch nails
  • 6 inch wood block
  • hammer
  • drill with a bit that is slightly larger than the nail
  • candle
  • bright enamel paint and a brush

WHAT TO DO:

  1. Drill a hole in one end of the dowel. the hole should be just slightly larger than the pointed end of the nail the hole should be about 1 inch deep
  2. Use one of the large nails to attach the wood block to the opposite end of the dowel.
  3. Carefully cut the balls in half with the sharp knife. Paint one of the halves with the paint. Tack/nail the balls to the ends of the thin sticks.
  4. Mark the center of each thin stick and Use the second long nail to join the 2 sticks together. Be sure the nail extends about an inch below the bottom of the sticks.
  5. Coat the bottom of this nail with candle wax by sticking the nail into the candle several times.
  6. Carefully set the nail into the hole that was drilled into the top of the dowel. The nail should turn easily in the hole.  
  7. Now you have to calculate the speed of your anemometer. Hold it out the window of the car while your mom drives 10 miles per hour. Count the number of times the colored ball turns past your hand in one minute. Divide this number by 10 to tell how f fast your anemometer turns at 1 mile per hour.
  8. Now you are read to measure the speed of the wind. Set the anemometer outside in a spot where it will catch the wind. Count the number of times the colored ball spins around past you in one minute. Then divide this number by the number you found for the speed of your anemometer at 1 mile per hour. This answer will tell you the speed of the wind for the day.

Sample calculations:

50 spins in 1 minute at 10 miles per hour
50 divided by 10 = 5 times at 1 mph

80 spins in the wind in 1 minute
80 divided by 5 = 16 miles per hour for the wind that day