The given picture illustrates the working of a hot air balloon. It shows the balloon in the ascending and the descending mode.
Overall, it can be seen that the hot air balloon is scientifically designed to allow it to ascend or descend,
and the controll of the burners and the valve is in the hands of the passengers.
The first picture shows the ascending hot air balloon. The gas cylinder tank is at the bottom of the balloon above which there is a basket which has arrangement for the passengers to sit or stand. When the burners are on, the balloon envelope inflates and rises up. There is a valve at the top of the envelope which is closed when the balloon is rising up. The cord of the valve is in the hand of the passengers.
The second picture shows the descending hot air balloon. It is evident that to make the balloon descend, the burners have to be extinguished and the valve cord is pulled, as a result of which the valve on the top is opened and the air is let out. All this deflates the balloon and the balloon descends.
