Drag it, lift it, thrust it, weigh it

1. Ask everyone ‘What do you think makes something fall slowly through the air?’
2. Explain that drag (also called air resistance) is a force that pushes against something as it moves through the air. It slows things down.
3. Explain that weight is the force that pulls things down. This happens because of gravity, which pulls everything toward the ground.
4. A parachute works by creating a lot of drag. It spreads out, catches the air, and slows down the fall. This makes landing much safer.
5. Split everyone into small groups. Each group will build and test their own parachute.
6. To build the parachute:
   • Cut a square out of plastic or fabric.
   • Attach four equal pieces of string - one to each corner -using tape or by tying.
   • Tie the ends of the strings together at the bottom.
   • Attach a small object (this is your payload) to where the strings meet.
7. With adult supervision, let each group drop their parachute from a height to see how it falls. 
8. After each drop, ask the group:
   • Did it fall fast or slow?
   • Did it wobble or float gently down?
   • Why do you think it fell that way?
9. If there’s time, let them drop it more than once to see if it changes.
10. Next, let groups experiment with the forces of drag and weight.

Experimenting with drag (air resistance):

• Try making a bigger parachute. Bigger parachutes catch more air and fall more slowly.
• Use different materials, such as paper, plastic bags or fabric. Some materials create more drag than others.
• Add small holes in the parachute. Holes let air pass through, which can make the parachute fall faster.
• At the end, ask each group to share what they found out.

Experimenting with weight (payload):

• Try using heavier or lighter payloads. Heavier ones fall faster because gravity pulls on them more.
• See how changing the weight affects how the parachute works.
• At the end, ask each group to share what they found out.

1. Start by explaining that thrust is the force that pushes a plane forward through the air.
2. Thrust happens when a plane’s engines push air backward, and that makes the plane move forward.
3. Without enough thrust, the plane wouldn’t move fast enough to lift off the ground, because drag (air pushing against it) would slow it down.
4. So, thrust helps the plane go fast enough to take off and stay in the air.

Now let’s build a balloon rocket to see thrust in action!

1. Ask everyone to get into small groups. Make sure each group has their balloon rocket materials.
2. Choose a space where you can stretch a piece of string between two objects like chairs, doors, or shelves.
3. Cut a piece of string long enough to go across the space.
4. Slide a straw onto the string. This will help the balloon ‘ride’ along the string like a rocket.
5. Stretch the string tightly between the two objects so it is straight and horizontal.
6. Use tape, drawing pins, or knots to hold the string tightly in place.
7. Blow up a balloon (but don’t tie it!). Hold the end closed by pinching it with your fingers.
8. Use tape to stick the balloon to the straw, right in the middle.
9. When you're ready, let go of the balloon. The air will rush out, and the balloon will zoom along the string!
10. This happens because the air escaping creates thrust, which pushes the balloon rocket forward.

Now try changing things and see what happens!

• Change balloon size: Bigger balloons can hold more air and might go further. But they are also heavier and may create more drag.
• Try different balloon shapes: Round balloons usually move faster because their shape lets air move around them easily. Odd-shaped balloons might slow down because of more drag.
• Add more or less air: More air gives a stronger push (more thrust), but also adds weight. See how this changes how far the rocket goes.
• Change how tight the string is: A very tight string might slow the balloon down. A slightly looser string might help it move more easily.
• Change the angle of the string: If the string tilts upward, the balloon may not go as far. A flatter string usually helps the rocket travel farther.

After each launch, ask:

• What made the balloon go faster or slower?
• What changed the distance it went?
• How did thrust and drag affect the rocket?

1. Ask everyone to get into small groups, and make sure each group has an adult.
2. Each group should fold a paper plane. They can use the instructions on the ‘Fold a Paper Plane’ sheet or make up their own designs.
3. Once the planes are ready, groups should mark their plane with a pencil. 
4. Line up on a throwing line with plenty of space.
5. Throw the planes gently for the first test. Then, once everyone has thrown their plane, go pick them up and throw again with more force.
6. Gather everyone back together and ask them what made their paper plane move forward. Then ask, ‘What moves a real aeroplane forward?’
7. Explain that for the paper planes, your hand gives the thrust when you throw it. For real aeroplanes, engines give the thrust. Thrust is the force that pushes something forward. After you throw a paper plane, it keeps moving because it has momentum. The harder you throw, the more momentum it has, and the farther it can glide.

Experiment with weight

1. Everyone should add a paper clip to their plane. This adds weight. A large paper clip weighs about the same as a paper plane.
2. Before throwing, ask everyone to predict if the plane will fly further, slower, faster, or differently with more weight.
3. Then test the planes again and see what happens.
4. Planes may need more thrust (a stronger throw) to carry the extra weight.

Experiment with flight path

1. Now remove the paper clip and look at the flaps at the back of the plane (the tail).
2. Fold up one flap on one side of the tail. This will make the plane turn toward that side when it flies.
3. Throw the plane and see if it curves in that direction.
4. Next, fold up both flaps. This can make the plane stall or slow down suddenly in the air.
5. Throw the plane and watch to see what it does.

Discuss the forces of flight

1. Gather everyone together and ask them if they can name the four main forces that affect flying and what they do:
   • Lift: Pushes the plane up.
   • Weight: Pulls the plane down.
   • Thrust: Pushes the plane forward.
   • Drag: Slows the plane down (air resistance).
2. See if people can answer these questions: 
   • Planes are super heavy - some weigh as much as 30 cars! How do they stay in the air? They need enough lift to fight against their weight.
   • What happens if a plane has too much lift? It goes up too quickly.
   • What helps a plane move forward from a stop? It needs thrust from the engines.
   • If a plane’s engines turned off when it was moving, what would happen? It would slow down because of drag.

Test the planes in the wind (if you can!)

1. If it’s windy outside, take the planes out and test how they fly in the wind. Talk about how wind direction and strength can affect take-offs and landings.

2. Now, see if the group can answer these questions:

• • If a plane flies into strong wind, what does it need more of to keep going? It needs more thrust.
  • What problems can wind cause during take-off or landing? The plane may have to work harder or go slower. 
  • What happens if wind blows at an angle to the plane? It might be harder to steer straight.