Who pushes the fire up? | Convection currents | English

In this Experiment, we will light a paper cylinder made of tea bag on fire and make it fly up in the air! As the bag completely burns out, it gets pulled up in the air due to the flow of air also called as convection currents. Let us learn more about convection currents with this fun experiment!

The convection current is the movement of fluids such as liquids and gases generated as a result of warm material rising up and cooler material sinking down. The heated material has a lower density and is thus lighter which makes it rise up. However, the cooler material being heavier (more density) sinks. This creates a circular motion of air around the fire and this makes fire rise up in the center.

When the tea bag is lit on fire, the air above the fire heats up, expands and rises up whereas the surrounding air which is cooler tries to take its place. This creates the convection currents of air in all direction around the tea bag. When the tea bag is almost completely burnt, it has hardly any weight and the flow of convection currents pulls the bag up in the air. This shows the effect of convection currents on the burning objects. Due to this same effect, we see the small pieces of burning material go up in the air above the fire.

Hope you learned something new today and understood the process of convection currents. For more exciting experiments about math’s and science subscribe to our YouTube channel.
Thanks!

Team: Ashok Rupner, Chaitanya Mungi, Neha Apte, Sajeda Sayyad_Shaikh, Pinki Saha, Students of NCL School Pune, Dr. B N Das