What will happen to the water in the paper boat in the experiment of burning it? What about the paper boat?

I remember one week in the third class on Thursday afternoon. In science class, we did a little experiment. The experimental method is: put a paper boat made of white paper on a tripod, pour a certain amount of water into the paper boat, and finally gently move the alcohol lamp under the tripod. What about the water in the paper boat? What about the paper boat? The students are talking about it. The teacher said, "Listening is false, but seeing is true. Let's start the experiment. "

I saw the teacher put the tripod on the table, put the paper boat prepared in advance on the tripod, and then poured half the water from the beaker. In the last step, the teacher lit the alcohol lamp with a match torch. Now move the alcohol lamp under the tripod until the water and paper boat have changed. After a while, we found that the paper boat was not burned and the water in it was still there.

Our mouth is wide enough to put down an egg. The teacher said: "The reason why the paper boat was not burned is because the material needs a certain temperature when it burns, because the water is constantly evaporating while the paper boat heats up." The water evaporates and the steam takes away the heat, so the paper boat won't burn until the water is dry. "

I see: in the experiment of burning a paper boat, the water in the paper boat won't evaporate? Paper boats won't burn down.

A 500-word essay on science and technology: Why do leather shoes shine brighter and brighter?

When the weekend came, my mother asked me to shine my shoes at home, and I readily agreed. I went to the shoe cabinet and looked at these dusty shoes. I have been polishing them. Suddenly, a question flashed through my mind. Why are leather shoes getting brighter and brighter?

Experiment: I found two pairs of old and new leather shoes of the same brand and style for comparative observation. I first touched the uppers of two pairs of leather shoes and found that the surface of the new shoes was much smoother than the old ones. Old leather shoes are coated with shoe polish. After careful polishing, it shines a lot, but it is still not as good as new leather shoes. Is there a relationship between the brightness of leather shoes and the smoothness of uppers?

I brought a pair of old leather shoes that were not polished, and the uppers were uneven under the magnifying glass. Then, I carefully wiped one shoe with shoe polish, and the other shoe without shoe polish was used as a blank control. I found that after the first piece was wiped, the surface became much smoother and brighter than the other piece in the sun. Why is there such a big difference between them?

Answer: I searched online and learned that the surface of leather shoes is not absolutely smooth. If it is an old leather shoe, its surface is of course more uneven and can't be reflected in a certain direction, so it looks dull. There are some small particles in shoe polish, which can just be filled into the pits on the surface of leather shoes when shining shoes. If you wipe it with a cloth again to make the shoe polish more uniform, the surface of leather shoes will become smoother and smoother, and the reflective ability will be strengthened.

I finally know why shoes are getting brighter and brighter. There are so many question marks in life!