See fire-balls (Gini bola) with Mathematics !

By Naleen Ganegoda (email : naleen_cg@yahoo.com)
Department of Mathematics, University of Sri Jayewardenepura

A procession (perahera) with fire-balls; Fire-balls with Mathematics. What…….?

You may aware that all fire-ball artists try to demonstrate circular motions using fire-balls. There are horizontal as well as vertical fire-ball displays. Whatever it is, main concern is to maintain a suitable speed to have a circle of fire.

Now, let us enter into Maths; . This is the basic equation that governs a circular motion. Here v – tangential velocity,  – angular velocity and r – radius.

How can we catch up these terms from a fire-ball motion? Let us consider a motion of one fire-ball. If we keep our eyes with the fire-ball, the speed of rotating our eyes corresponds with w. Watch artist’s hands too! If w is high, hands are too quick. Now for v, keep your eyes in a particular point at the fire circle and try to tackle the speed of the fire-ball, when it is passing through that point. That speed is corresponding to v.

To display a fire circle, artists should maintain v appropriately in a higher value. Then relevant w is decided according to the length of the rope or stick that attaches the fire-ball. r represents this length. So, fire-ball artists are good users of Maths!

Finally, think of this as well.

“Don’t choose a position closer to the centre, when you are in a Merry-go-round”

Why is that? Guess the trick with .