Do the following: strike the matchstick to the rough portion of the matchstick box. Let it burn for a while, then observe what happen.

1.What kind of energy is stored in the matchstick?
2.What happen to the matchstick when you strike it to the rough surface of the box?
3.When the matchstick burn what is produce?
4.Was there energy transformation?
5.Why do you say so?

Light from two different sources are incident upon the same side of a polarizing filter. light from one source is polarized with total intensity ip, while light from the other source is unpolarized with total intensity iu. as you rotate the polarizing filter through 360 degrees, the intensity of the transmitted light on the other side varies by a factor of 9. what is the relative intensity of the initial polarized source to the unpolarized source, or ip/iu?