What you need:
- An A4-sized sheet of paper
- Scissors
- A paperclip Pencil and ruler
What to do:
1. Divide the A4 sheet into four parts horizontally. Cut off one part so you have a paper strip.
2. On the strip, copy the shape shown in the figure.
3. Cut along the solid lines and fold along the dotted lines.
4. At the bottom of the T-fold, secure the flaps using the paperclip. At the top of the T. the two legs need to be folded in opposite direction to make the rotor (the fan-like thing) on top of the helicopter.
5. That’s it! Now, hold the helicopter high and let it go!
What happens:
The paper chopper whirls as it descends slowly to the ground.
Why?
When you let go of the helicopter, it falls under the influence of gravity. But its rotor (the two blade-like things) helps it stay afloat longer. This is because the air pushes against the flaps separately, causing them to lift up. When the flaps are lifted, they slant. Air hitting the slanted flaps gives them a sideways, horizontal push causing the copter to rotate and create more air movement around the flaps. This moving air helps the chopper float. In real life, airplanes achieve lift with the help of their wings. To do so, airplanes have to first move really fast so that the air can flow over their wings and lift them up. That means they cannot take off without a runway. That’s where helicopters have an advantage. They use their rotors to create fast-moving air that can give them a lift easily.
Picture Credit : Google
