The Science Behind Matchbox Experiments for Beginners

[Oomph!]

Hello.
I saw this experiment:
You need only matches and match box. I tried it and I it works. However, I want understand it in physics view. Please, is there anyone who can give me explanation how it works?

Thank you very much!

 

[Bandersnatch]

Hi Oomph,

There's two things going on: the heads fuse together when lit, and the angled match is burning unequally fast on its upper and lower edges. The first effect makes the matches stick, and the second makes the angled one bend upwards.

You can observe that many materials have a tendency to fuse when heated or set on fire. Plastic is a good example, and some artificial textiles are infamous for fusing with burnt skin(which is why not every material is equally good for using as a blanket to put out flames).

The second effect can be also observed with single matches - they'll tend to bend upwards when held horizontally, and stay more or less straight if held vertically. The horizontal(or inclined) match has got higher temperature on its upper edge due to the flames going upward, so it burns more vigorously there. A burnt material tends to contract, and so the match contracts more on one edge than on the other.

The "levitation" in the video title is of course nothing of the sort. It's just a match glued to another sticking out at an angle.

 

[Oomph!]

Thank you very much!
However, why does the materials have tendency to fuse when heated from the view of molecular physic? Higher temperature - higher displacement of particles - larger effects of forces? Or why?

 

[Oomph!]

And I don't understand why does the horizontal match has got higher temperature on its upper edge. Normal verticall match has same temperature on upper and bottom edge? Why? How does the temperature relate to bend the horizontal match?

 

[phinds]

And I don't understand why does the horizontal match has got higher temperature on its upper edge. Normal verticall match has same temperature on upper and bottom edge? Why? How does the temperature relate to bend the horizontal match?

You misunderstand. Vertical matches do not have the same temperature on upper and lower parts, they have equal temperature all the way around so no one area changes shape slower/faster than another.

 

[A.T.]

And I don't understand why does the horizontal match has got higher temperature on its upper edge.

The simple answer is: Hot gases are lighter and go up.

How does the temperature relate to bend the horizontal match?

http://research.cs.tamu.edu/keyser/graphics/people/melek_Z_files/sig06_poster.pdf

Wood and paper are both fibrous materials. Heating of a fibrous material causes water to be driven out of the matrix and the fiber to contract. The ends of the heated fibers are thus drawn together. As a match burns, the region around the flam e gets hot, but a heat differential occurs due to the shape of the flame. The top of the match gets hotter than the bottom , and thus the top part contracts m ore than the bottom . For small pieces of wood (like matches), this contraction is enough to cause an upwards bend.

 

[Oomph!]

OK, thank you. Now I understand. However, still I have the question - why does the materials have tendency to fuse when heated from the view of molecular physic?

 

[A.T.]

However, still I have the question - why does the materials have tendency to fuse when heated from the view of molecular physic?

Heating breaks the molecular matrix and allows it to form new.