08 Physics knowledge in Xiangyun Torch

On December 21, 2006, the 2008 Olympic torch "Xiangyun" was officially submitted to the Beijing Olympic Organizing Committee. The torch is 72 cm high, weighs 985 grams, burns for up to 15 minutes, can keep burning with wind speeds of 65 kilometers per hour and rainfall of 50 mm per hour, and has a flame height of 25 to 30 centimeters at zero wind speeds, allowing it to be identified and photographed in bright light and daylight. The lower half is sprayed with high-touch red plastic paint, which is comfortable to the touch and not easy to slip off.

The fuel used in the flare is propane, which is a very inexpensive and commonly used fuel. Its main components are carbon and hydrogen, and after combustion, there is only carbon dioxide and water.

1) 65 kmh, m/s; (Keep one decimal place) 2) The density of the material used to make the torch "auspicious cloud" should be small ("larger" or "smaller" should be selected after estimation);

3) The lower half of the torch is sprayed with high-touch red plastic paint, which increases friction.

Red is eye-catching.

Because red light has the longest wavelength and the strongest penetration in air.

According to reports, the shell of the "Xiangyun" torch is made of bright and thin aluminum alloy materials. The person in charge of the torch design said that due to the strict requirements for the weight of the torch, the Beijing Olympic torch cannot exceed 1,500 grams, and the torch will make it difficult for the torchbearer to hold it, so aluminum alloy was chosen. On the one hand, the aluminum alloy is lighter, with only 985 grams of "auspicious clouds", and the bright silver color also gives the torch a modern look.

1.The main component of the shell of the torch is: aluminum, mainly from the physical and chemical properties of aluminum. There will be a dense oxide film on the surface of the air, which can prevent air corrosion.

2.The fuel for the torch is propane (C3H8), and the fuel used for the Beijing Olympic torch is propane, which is a cheap common fuel. Its main components are carbon and hydrogen, and after complete combustion, there are only carbon dioxide and water, and there are no other substances, which will not cause pollution to the environment.

In May 2008, the Beijing Olympic torch relay crossed the world's highest Mount Everest, and the "Xiangyun" torch needed oxygen for the combustion of propane, which was to take advantage of the nature of oxygen (to support combustion).

Mountaineers need oxygen for breathing, which shows that oxygen has the purpose of (supplying breathing), oxygen and the body's glucose undergo a slow oxidation reaction to produce carbon dioxide and water, providing the energy required by the human body, write the literal expression of the reaction: (

Glucose + Oxygen Carbon dioxide + water.

1) What is the approximate weight of the torch? The weight of the torch is about; 2) What are the benefits of using propane as fuel? Propane has a low ignition point, and the products produced by propane combustion are water and carbon dioxide, which is more environmentally friendly;

3) Why is the torch shell made of thin aluminum alloy? Because this aluminum alloy has a low density and light weight.

The answer is not unique).

(1) Torch bai

What is the approximate amount of weight du? The weight of the torch is about;

2) Use zhi

Propane as fuel has DAO

What are the benefits? The ignition point of propane is low, and the volume generated by propane combustion is water and carbon dioxide, which is more environmentally friendly;

3) Why is the torch shell made of thin aluminum alloy? Because this aluminum alloy has a low density and light weight.

The answer is not unique).

The torch "weighs 985 grams", and the mass of the torch should be 985 grams in the standard physical language;

Because the density of aluminum is small, so that in the case of the same volume, the smaller the density, the smaller the mass, the more the metal material aluminum is used in the shell of the torch

Therefore, the answer to the loss case is: the mass of the torch is 985g; ②d

1) The torch "weighs 985 grams", which should be expressed in standard physical language as the mass of the torch is 985 grams;

2) The torchbearer has to run a distance with the torch, so reducing the quality of the torch is the main problem, so Lu Lu suspects that the shell of the torch is made of aluminum, which is mainly because the density of aluminum is small, so that the torch will be lighter;

So the answer is: (1) the mass of the torch is 985 grams, (2) d

1) The torch is red because it can only reflect red light and does not reflect other colors of light, so the reason is: the main part of the torch reflects the red light in the daylight and absorbs the light of other colors;

2) The mass repentance of the torch: m=985g=, the gravity of the torch: g=mg=, because the torch is stationary, so the vertical upward force and gravity of the torch are a pair of balanced forces, then f=g=;

3) There are two ways to liquefy the gas: one is to reduce the temperature, and the other is to compress the volume So if you want to change propane from gaseous to liquid at room temperature, we can take the method of pressurization to liquefy it at room temperature, and this process needs to release heat

Therefore, the answer is: the main part of the torch reflects the red light in the daylight and absorbs the light of other colors; compressed volume; Release

(1) When the torch is held at rest, the torch is subjected to the action of a balancing force, that is, the gravity of the torch and the friction force of the torch are a pair of balancing forces; It is precisely because the torch is subjected to the upward friction of the hand on it that it does not fall;

2) The magnitude of the equilibrium force is equal, that is, the frictional force f=g=mg=;

So the answer is: (1) friction; （2）