Summary
Make a tissue paper hot air balloon and then fly it on a thread.
Background
Hot air is less dense than cold air. This makes a blob of hot air rise and float above the surrounding air. If a light bag is filled with hot air it will float with air inside provided that the density of the bag and air inside is less that the surrounding. In the 1700s in Europe engineers design floating balloons that were filled with air heated by a fire. Today hot air balloons heated by propane burners are a common sight.
Materials
- Colored tissue paper-18 pieces
- White glue or glue stick
- thread
Tools
- Scissors
- Hot air gun or hair dryer
Directions
- Glue 3 pieces of tissue together along their narrow edge creating a long
narrow sheet with alternating colors. The glued edge should be just a quarter to half an inch wide. Make 6 assembled sheets. - Trace the design of a gore on the top shape.
- Cut out all the sheets along the line traced on the top sheet.
- Glue the gores together so the seam is flat as possible, fold or crinkle the pieces as needed to make a nice flat seam.
- Reinforce the bottom opening with a ring of construction paper.
- Poke 2 or 3 holes in the reinforced tube and make a halter with the thread. The thread should be very light so it doesn’t weight the balloon down,
Flying
On a cool windless day…
- Have someone stand a chair to hold the balloon vertical, or loop the balloon over a long stick that is stuck in the ground.
- Place the heat gun in the opening and blow hot air in. Be careful you don’t singe the tissue.
- As the balloon fills with hot air it will begin to lift and tug on the thread.
- When you are ready remove the heat gun and let the balloon rise while holding on to the thread.
Grade