|Let’s go fly a kite!|
|Written by Jennifer K Mahal|
Let’s go fly a kite! April is a breezy month, perfect for sending colorful kites soaring in the air.
Making a homemade kite is simple, easy and a lesson in physics. Getting it to fly, however, can be a challenge. All flight — whether it’s a kite or an airplane — is affected by four forces: lift, drag, thrust and gravity.
Lift is the force created by a kite moving through the air. It is created by differences
in air pressure, in other words the way air moves over the body of a kite. In the 1700s, a scientist named Daniel Bernoulli discovered that fast-moving fluids exert less pressure than slow-moving fluids. Air is a gas, but it behaves like a fluid. The Bernoulli Principle helps explain why kites fly. As the air over the top of the kite goes faster (because of wind or someone running), it has less pressure than the air below the kite, which allows the kite to soar, defying gravity.
Gravity is the force that makes us all stick to the earth. Without gravity, everything would be floating in the atmosphere. Kites have to have enough lift to overcome gravity.
Kites are also affected by drag and thrust. Drag is created by wind resistance to the kite’s body and tail. The tail, while slowing the kite down, also allows it to stay stable. Wind creates thrust, the forward force that makes a kite move. Just as gravity and lift have to be in balance, drag and thrust need to be in balance to make a kite stable.
You can learn more about the forces of flight at the Smithsonian National Air and Space Museum’s How Things Fly website: http://howthingsfly.si.edu/.
To make a flat diamond-shaped kite, you will need:
* A Sheet of Newspaper
* Two sticks (we used wooden barbecue skewers)
* School Glue
* Scrap pieces of Fabric
* Markers or Crayons to decorate
Decorate your newspaper. Make sure to use markers, pencil or crayon rather than paint. Paint adds weight. If you want a colorful kite with less work, you can use the Sunday comics instead.
Take your two sticks and make one stick slightly smaller than the other. If you are using barbecue skewers, have a grownup cut the sharp tips off and make one skewer an inch smaller.
Put the smaller stick across the larger stick, so it forms the shape of a lower-case t. Tie the two sticks together with string, winding around the two sticks in an X pattern to keep the sticks at a 90 degrees angle.
Starting at the bottom of the lower-cased t, tie your string. Leave enough of a tail of string to tie on a longer tail later. String the string around the four ends of the stick, winding each time to keep the string in place. You may need to have an adult cut small notches to help the string stay. This will give you a frame with a diamond shape.
Lay the frame on top of the piece of newspaper. Cut the paper so you have a diamond shape about 2 inches larger than your kite frame. Now fold the edges of the newspaper over the frame. Glue those edges down. Let the glue dry for an hour or so.
Place a piece of tape in the middle of the front side of the kite, slightly above where the sticks cross. Put a second piece of tape a few inches below where the sticks cross. Have an adult carefully poke small holes through both spots.
Take a piece of string about 10 inches long and poke one end through each hole. Tie each side to the center stick. This will be the bridle.
Tie a piece of string at least 3 times the length of your kite to the string you left at the bottom of the diamond. Tie pieces of fabric to it in intervals.
Now tie a ball of string to the bridle and find a windy place to fly it! The beaches in Santa Cruz County are fabulous kite flying spots, since there’s always lots of wind and very few trees.
There are several ways to get a kite started flying. You can have a friend launch it in the air as you run, or you can run with a long lead string and pull it in as you run, making the kite rise. Whatever way you choose to fly your kite, remember to have the wind blowing towards you.
Discover more science and art at the Santa Cruz Children’s Museum of Discovery in the Capitola Mall. Learn more at www.sccmod.org.
Jennifer K Mahal, who writes children’s books under the name Jenni Kaye, is a volunteer with the Santa Cruz Children’s Museum of Discovery. She lives in Santa Cruz with her husband and two children.
|Last Updated on Monday, 03 April 2017 13:00|