Tie a knot at one end of a 2-meter long flexible plastic tube used for making plastic bags. This will seal that end. Then blow a lungful of air with your mouth next to the tube. This will be a measure of your lung capacity. Next keep the tube end 20-cm away from your mouth and blow again. Much more air will fill in the bag this time because of the Bernoulli Effect.
http://www.arvindguptatoys.com/toys/bbag.html This work was supported by IUCAA and Tata Trust. This film was made by Ashok Rupner TATA Trust:
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