Bottle Barometer | Kannada | Fun with Pressure
Channel: Arvind Gupta
Date: 2015-02-17

This is a fun experiment using a cut out bottle. It is called as the Bottle Barometer. To make this you will need a 500-ml stiff coke bottle, a pen and a scissors. Now mark a half circle on the bottle right in its middle as shown. Then cut along the semi-circle. Now try and press the cut portion inwards. Because of the stiffness of the bottle it will take some effort to press the cut portion below. Now the Bottle Barometer is almost ready to experiment with. You will have a cut bottle with its top part pressed below. Remove the lid of the bottle and then completely immerse it in a color water bucket. On removing you will find that only half the bottle will be filled with water. Now, dip the bottle again in water and then screw on its cap. On lifting, this time you will find that most of the pressed top portion of the bottle will also be filled with color water. Why does this happen? Well, the open surface of the water in the bottle is subjected to atmospheric pressure. And it is this pressure which supports the raised column of water in the pressed and closed portion of the bottle. If you place a Styrofoam ball it will immediately float to the top. On removing the lid from the bottle the water from the top will be drained out. This is because then the raised portion of water on the top will also be subjected to atmospheric pressure. Here the children are experimenting and having fun. This work was supported by IUCAA and Tata Trust. This film was made by Ashok Rupner TATA Trust: Education is one of the key focus areas for Tata Trusts, aiming towards enabling access of quality education to the underprivileged population in India. To facilitate quality in teaching and learning of Science education through workshops, capacity building and resource creation, Tata Trusts have been supporting Muktangan Vigyan Shodhika (MVS), IUCAA's Children’s Science Centre, since inception. To know more about other initiatives of Tata Trusts, please visit www.tatatrusts.org