Page 59 - Grasp English B2 (Student Book)

|
Science Aeronautics

Materials
For this experiment, you need:
Project 2 • one plastic trash bag

E. Work in pairs and discuss the following questions. • five paper clips
• one hairdryer
1. What is a hot air balloon?
• string (50 cm)
2. How do they fly?
• scissors
3. Can people travel long distances with hot air balloons? Why?

F. Read the experiment to the right and make your own hot Instructions
air balloon. Tie a string around the top of the plastic bag.
It should look like the bottom of a balloon. Tie
the bag up, knot the string tightly, and cut
off any extra string. Add paper clips around
the bottom of the bag to increase the
weight of the bag. The weight will balance
and stabilise your balloon when it starts
floating. Turn on the dryer to high and fill the
balloon entirely with hot air. The bag will start
to float, and when it does gently release the
bag. The hot air inside the balloon is lighter,
causing it to float.

57