Water Fountain by Balloon | English

Hello friends, today we are making a very innovative water fountain by using a balloon. In this video, we'll show you how to make a multiple water fountains by using a single balloon. For this, we need some materials like three uniform bottles, three bent straws, two pieces of pipes, a balloon, a scissors, a glue, and coloured water.
First, make a hole in the plastic bottle near the neck by using the scissors. Insert the bent straw into the bottle such that the end of the straw should touch the bottom of the bottle. Secure the hole of the plastic bottle with glue and let the glue dry for about half an hour. After completely drying the glue, place the bottle in the tray and fill it completely with coloured water. Now inflate the balloon to its medium size, hold the neck of the balloon and fix the balloon to the mouth of the bottle. Make sure that there is no air leakage from the balloon. When you remove the hand from the balloon's mouth, you will see the beautiful water fountain start from the bent straw. You must be like the water fountain coming from the straw. Now let’s understand how this fountain was formed. When we blow up a balloon, the air goes from our lungs and hits the walls of the balloon—this creates air pressure in the balloon that forces the balloon to inflate. Due to the elasticity of the balloon membrane, the balloon tries to reduce the volume of air in the balloon, and, as a result, the pressure of the air inside the balloon increases. Due to this, the air pressure inside the balloon is always greater than the outside air pressure. When we attached the high-pressure balloon to the mouth of the bottle, the pressurized air tries to enter the bottle, causing the water from the bottle to gushes out through the straw, resulting in the formation of a beautiful water fountain.
Now let’s make some modifications to this activity. Take three bottles and make holes nearer to the base of all three bottles and join them together with the help of hard plastic pipes as shown. Secure the holes with glue, so that there should be no leakage of the water. Again, make holes nearer to the neck of all three bottles and insert the bent straw into each bottle. Again, secure the holes with glue. Fix the bottles on the wooden plank with the help of the glue and wait for the glue to dry. When the glue dries, remove the caps from the bottles and fill them completely with coloured water. Fix the caps on the bottles. Place the bottle in the tray so that we can collect the water in it. Again, inflate the balloon and fix it to one of the bottles. When we remove the hand from the balloon, the air tries to get into the bottle, and due to this air pressure, you can observe beautiful water fountains coming from all three bottles. If you look here carefully, you will see that only one bottle got empty and not the other two. Even though the water fountains came from all three bottles, the water level in the two bottles shows its original level.
Now the question is how to empty all three bottles. When you squeeze the balloon, due to the applied extra pressure, you can remove the water from the other two bottles as well.
Now let’s make one more modification. Use another set of the materials and make the same assembly as we did in the earlier activity, but make the holes nearer to the neck of the bottles and fix the pipes in it. Again, secure all the holes with the glue. Fill the three bottles with coloured water. Place the bottle assembly in the tray. Remove the cap of one of the bottles and fix an inflated balloon on it. When we release the hand, you will again find three water fountains. The main difference here, as compared to the earlier activity, is that the water level in all three bottles has been reduced, whereas, in the earlier activity, the water level in only one bottle was reduced.
The basic principle of these activities is the same as we discussed earlier, with the help of the single water fountain. Here, either water or air can transfer from one bottle to another bottle. In the three-bottle assembly named "A", we fixed the pipes at the bottom of the bottle, so water goes from one bottle to another bottle. Whereas in the assembly named "B," air can go from one bottle to another two bottles.
I hope you will like this experiment very much, and you can do one such model in your home. Thank you very much.

Team: Prof. Harinath Chakrapani, Dr Sourabh Dube, Dr Aparna Deshpande, Shubhangi Wankhede, Ashok Rupner, Dr Neeraja Dashaputre, Dr Chaitanya Mungi, Ankish Tirpude, Shraddha Bhurkunde, Dinesh Turkar, Pradnya Pujari, Sakhee Bhure, Dr Apurva Barve, Dr Asim Auti, Shanti Pise, Rohit Piwal and Science media centre team of IISER Pune.