EXPERIMENT TO SHOW HOW A HOT AIR BALLOON WORKS?

In this experiment you see how  hot air balloons work!!

Materials:

1plastic dry cleaning bag

Hair dryer

                        

Instructions

Open the bag and fill with air by pulling it quickly through the air around you.

Close the bag put leave a small opening in it, so that you can fit a hair dryer.

Heat the air inside the bag with the help of hair dryer for at least 10-15 minutes.

Observe: The bag rises

What is happening?

As air is warmed, the molecules spread out. This makes the  
Air lighter and hence it rises.

 As the air in the bag is warmed it expands and rises.

 
The rising warm air fills the bag and causes it to rise.

 This is how a hot air balloon works!