Sci-fun

Sci-fun is a program created organised and conducted by Dr. Anna Neena George, Associate professor, G.V.M's Dr. Dada Vaidya College of Education. The program is based on ideas of Arvind Gupta, of using low cost and throw away materials to make 'Sci-Toys' to teach Science.

I was a part of sixth year Sci-fun program 2016-2017. This year we visited 6 schools, namely

• MIBK High School, Khandepar- Goa
• GVM's Pragati Vidyalaya High School, Borim-Goa
• Government High school Sadar, Ponda-Goa
• Dr. Sakharam Gude high School, Shiroda
• Government High School, Juna Bazar Ponda
• Shree Sharda English High School Sanvordem.

Experiment name: Balloon in a bottle

  Concepts: Air occupy space and  air pressure difference

student performing experiment

student explaining concept using chart

 

Me explaining concept

Although air is invisible, it still takes up space and has weight. This is evident when the balloon is placed inside the bottle and you try to inflate it. It’s nearly impossible to add any amount of air! When the bottle with the hole is used, however, inflating the balloon is nearly effortless. The air inside the bottle is able to escape, freeing up space for the balloon to now inflate. If you then plug the hole on the outside of the bottle, the balloon will remain inflated. How does this happen? What keeps this air in place? This is a consequence of the air pressure being lowered inside the bottle when its hole is plugged. If the hole is then plugged, the balloon stays inflated even when the mouth is removed. This is because the high pressure air in the balloon pushes outward harder than the low pressure air in the bottle. The air in the balloon pushes out against the walls, keeping it inflated. When the hole is unplugged, air flows back into the bottle. The air pressure in the bottle increases and collapses the balloon.

 DID YOU KNOW?

When we flying in an aeroplane at high altitudes, more than 3000 m above sea level, the air pressure is very low and this can be dangerous for our health. At high altitudes under low air pressure, humans can suffer from a range of sicknesses such as hypoxia, altitude sickness, decompression sickness and barotrauma. To prevent these sicknesses aeroplanes flying at high altitudes pump air into the cabin to make the air in the cabin more compressed. The air inside the aeroplane is under higher pressure than the air outside the aeroplane. This is called “cabin pressurisation”.