If you throw a plain straw, it doesn’t go very far. But when you add paper hoops, the straw glides through the air!
EXPLAIN
It’s because the hoops act like wings. Things that fly, like insects, birds, and airplanes all have wings. But wings are not all the same shape and size. Different wings can be better for different kinds of flight. For example, an eagle has long, wide wings that help it glide. An airplane has wings with small flaps that move up and down to turn the plane. Try changing the wings on your glider. How does it fly with different wings?
EXPLORE
What you need:
• Paper
• Ruler
• Scissors
• Pencil
• Tape
• Non-bendable, plastic drinking straw
What to do:
1.Cut two strips of paper. Make one strip 1 inch wide and 5 inches long. Make the second strip 1 inch wide and 10 inches long.
2.Curl each paper strip into a hoop. Tape the ends together. Now you have a big hoop and a small hoop.
3.Tape the small hoop to one end of the straw.
4.Tape the big hoop on the other end of the straw. Make sure the big hoop lines up with the small hoop.
ELABORATE
Newton's 3rd Law of Motion: For every action, there is an equal and opposite reaction.
Thrust is the force exerted when to throw a hoop glider.
Drag (or air resistance) is the reaction force against thrust. The more "stuff" there is, the harder it is to move that stuff through the air.
Lift is the force that keeps a hoop glider up in the air. The curved surface of the hoop glider's loops create a difference in pressure above and below the loops, which deflects the hoop up.
Gravity is the reaction force, pulling the glider down toward the center of the Earth.
Gravity is a constant and cannot be changed. But by maximizing lift, minimizing drag and with just the right amount and direction of thrust, hoop gliders can fly quite far!
EVALUATE
Hold your Hoop Glider in the middle of the straw, with the small hoop in front. Throw it gently like a spear. It might take some practice to get the hang of it. How far does your glider fly?
EXTEND
What will happen if . . .
• you make the straw smaller?
• you change the size of the hoops?
• you add a third hoop?
Choose one thing to change (that’s the variable), and predict what you think will happen, then test it!
Other websites to check out
Science Bob's The Incredible Hoop Glider
The Exploratorium's Science Explorer Hoopster
Museum of Science Hoop Glider Engineering
PBS Kids ZOOM Hoop Glider PDF
