## Introduction: Engineering a Hoop Glider

Would you like to make your own flying toy, but you’re tired of paper airplanes? Try making a hoop glider, instead!

Hoop Gliders move through the air using the same forces that larger airplanes use when they fly. Those forces are thrust, drag, lift, and gravity. For this activity, your hand and arm will provide the thrust that push your glider forward. At the same time, the force of drag pushes against the glider in the opposite direction. We will use thinner, lighter materials in the construction of the glider to reduce this pushing force, and a larger loop on the back of the glider to use the force of drag to keep the glider upright! The Bernoulli Principle tells us that when faster moving air moves against an object it creates higher pressure systems and lower pressure systems. With these gliders, we’ll capture the slower moving air (a higher pressure system) in the hoops, providing the force of lift that will keep the glider in the air. And we can’t forget about the force of gravity that is always working on objects close to the Earth and pulling them down. Eventually this force will bring our gliders down to land.

## Supplies

• 1 Toilet Paper Roll (with no toilet paper on it!)
• Plastic or Paper Drinking Straw (if available)
• Scotch Tape
• Ruler
• Scissors
• Pencil

## Step 2: Unfold and Measure

Unfold the toilet paper roll and use the ruler to measure out 1” (or 1 inch. It also equals 2.5 cm) along the side of roll you cut. Using your pencil, place a mark at the 1” position. Continue placing marks on the roll at the 2” and 3” positions. You should now have 3 pencil marks on one side of your toilet paper roll. Follow the same instructions on the opposite side of the roll until both sides have pencil marks.

## Step 3: Draw Lines

Once again, use your ruler, this time drawing a line connecting your first pencil mark to the opposite mark on the other side of the roll.

Draw lines to connect the remaining marks on the original side of the roll to the marks on the opposite side (see picture, below).

## Step 4: Cut All Strips of Cardboard

After you finish cutting, you should have four cardboard strips from your toilet paper roll.

## Step 5: Prepare Your Straw

If your straw is in a wrapper, unwrap it, now. If you don’t have a straw handy, never fear. You can easily make a straw-like object by taking an 8”, or 11” long piece of paper and rolling it lengthwise into a tube. Tape the paper tube so that it doesn’t unroll while you’re making your hoop glider!

## Step 6: Prepare Hoop 1

Curl one of the cardboard strips into a loop and tape the ends together. (The cardboard should easily return to the curve of the roll). We call this loop a hoop! The hoops will catch the air in a higher pressure system that gives the glider lift to stay aloft.

## Step 7: Prepare Larger Hoop 2

Now make a larger hoop by taping two cardboard strips together into one large hoop.

## Step 8: Tape Straw to Inner Side of Hoop 1

Now that you have your two hoops, tape one end of the straw to the inside of one loop (as pictured, below).

## Step 9: Tape Straw to Inner Side of Hoop 2

Tape the opposite end of the straw to the inside of the second loop. Make sure that both loops are taped to the same curve of the straw (seen in the picture, below)

## Step 10: Experiment

You now have a completed Hoop Glider! To fly your glider, make sure the smaller loop is facing away from you, hold the straw in the middle with the hoops on top, angle the front slightly up, and throw it in the air gently, similar to how you might throw a dart.

Show your friends how to make one and hold a race!

## Step 11: Further Learning and Experimenting

For future hoop glider activities, try making your glider with other materials, alter the length of the straw, size of the hoops, or add additional hoops. Ask yourself the following challenge questions:

· Does the weight of the hoop glider make a difference in how far it flies?

· What materials make the glider fly further?

· What happens to the flight distance with a longer straw? Shorter?

· Can you calculate the velocity of your hoop glider flight? How about the momentum?

## Step 12: ​Key Terms/Vocabulary

Air – The collection of small molecules and atoms made of different gases that makes up Earth’s atmosphere. Air does have weight, takes up space, and can be contained within objects!

Air Pressure – The weight of air molecules pressing down on the Earth. Moving air can create differences in pressure from lower to higher pressure systems. Air pressure is the highest at sea level where the molecules are pushed the closest together!

Atmosphere – The layer of gases surrounding the Earth kept in place by the force of gravity. The atmosphere is what plants and animals (like humans!) need to breathe to survive.

Bernoulli Effect – The theory that says that when air moves around an object it will create different amounts of pressure on the object. Faster moving air will create lower pressure and slower moving air will create higher pressure systems.

Drag – A force produced by air that slows an object down as it moves through the air. The force of drag moves in the opposite direction to the motion of the object and increases the faster the object moves. Drag is also known as wind, or air resistance!

Force – Simply put, a push, or a pull on an object. A force can cause an object to accelerate, slow down, remain in place, or change shape.

Gravity – An invisible force that pulls objects toward each other. The larger the mass of an object the more gravity it has. The closer two, or more objects are to each other the more stronger the pull of their gravity. Gravity is why we are pulled down to the ground (also known as the planet Earth)!

Lift – The force that pushes “up”, directly opposing the force of Earth’s gravity and an essential component when discussing flying objects. The air pressure moving underneath the wing of an airplane is the lift that allows it to stay in the air.

Momentum – The measurement of movement. When an object is moving, it has momentum. Momentum can be found by multiplying the velocity of an object by its mass (or, how much matter is inside of the object).

Thrust – A pushing force that accelerates an object in the opposite direction to drag. A plane uses engines to thrust it forward to gain enough speed that allows the air pressure to lift it into the air!

Velocity – The rate of change in an object’s position. Velocity can also be described as the speed an object moves in a specific direction. It measures how much distance the object moves in a certain amount of time.