Go Fly a Kite

“Let’s Go Fly a Kite.” I can hear the song, made popular by the movie Mary Poppins, in my head. As the Queen of Science, one of the highlights of the year was building and flying kites. Lizzy reserved this activity for the third-grade students in her school, but kites can cause the spirits of kids… and adults to soar.

“There is a lot of science that keeps a kite or eagle in the air.”

The Mystery of Flight

The four forces of flight (i.e. Lift, Weight, Drag, and Thrust) affect kites in the same way they affect airplanes, eagles, and anything that flies. Kites are great for teaching the physics of all four forces, but we’ll focus on lift, or the upward force that pushes a kite into the air. The big flat part of a kite is called the sail. As it flies through the air, the sail is tilted with the back being lower than the front. The tilte or angle of the sail is critical to creating lift. The tail weighs down the back of the sail, helping to keep the kite tilted. The tilt changes the way air flows over the kite.

The tilt causes the air moving over the top to move faster than the air moving over the bottom. Daniel Bernoulli, an 18th century Swiss mathematician, made an amazing discovery. He found that the pressure of a fluid (like air) decreases as it speeds up. Since the speed of the air above the kite is greater than the speed below it, the pressure above is less than the pressure below. Low pressure on top and high pressure on the bottom causes the kite to climb.… that is the mystery of flight.

Learning From Experience

Over the years, Lizzy tried a lot of kite designs. With the goal of having every third-grade student (about 120) experience success, Lizzy found that “wind sled kites” were pretty much guaranteed to fly. Also, the large flat sail provides a lot of space for creating custom artwork. Of course, you can make your own, but the Frustrationless Flyer kit is just like it says, frustrationless. Lizzy purchased kites in bulk, but, if you do a quick Internet search, you can find  a kit for about $8.00. Each kit includes everything you need, a pre-cut kite sail, two wooden dowels, and a pre-measured bridle. This kite does not require a tail to fly, but you can add streamers to dress it up. What you will need are a hole punch and permanent markers for the artwork.

Kites fly best in 5-15 mph winds. You can feel wind in this range or see leaves rustling in the wind. Wind more than this, enough to make tree limbs toss, and it is more difficult to fly.

There is a lot of science that keeps a kite or eagle in the air. Kites are just one more wonder of the world that God has provided us. “Oh, let’s go fly a kite, up to the highest height. Let’s go fly a kite and send it soaring…” Now, it’s your turn, go fly a kite.

“But those who hope in the Lord will renew their strength. They will soar on wings like eagles; they will run and not grow weary, they will walk and not be faint.”

—Isaiah 40:31

Copyright © 2023 Chuck Locklear

also, see Science Can Be Fun.