Glass glass can be used to drink water, brew tea, juice drinks, etc. according to the purpose; it can be used as a glass craft gift, glass promotional gifts, souvenirs, etc.; according to the material, there are crystal cups, tempered Glass, etc. If the glass is combined with physics knowledge, what role does the glass play, and what physical knowledge does the glass have? Let"s talk about the physical common sense of the glass cup.

　　The physical properties of the glass are mainly in the four aspects of acoustics, optics, thermals and mechanics.

　　Acoustic aspect

　　1. Use the chopsticks to lightly hit the mouth of the glass, and you will hear the glass making a crisp and pleasant sound; when the chopsticks are not used, the glass will not make a sound. It means that the sound is generated by the vibration of the sounding body; when the vibration is stopped, the sound is stopped.

　　2. Put different quality waters in several identical glasses to make the water surface different. When using chopsticks to lightly tap different glass cups, you will get a different kind of "music". It means that the length of the sounding body is different, and the tone of the sound is different.

　　3. If you use two glasses of different thickness, use a chopstick to lightly hit the cup, you will find that the sound of the two cups is different. This is also a way to judge the quality of the bowl, cup, plate, etc. when we buy it in the market.

Optical aspect

　　1. Fill the glass with a glass and put it in the sun. You will find a colorful band on the back of it. Explain the dispersion of light.

　　2. Put a coin in the glass. The person retreats to the point where he can"t see the coin, then add water to the glass. As the amount of water added increases, he will see the "coin". Explain that light refracts when it enters the water from the air.

　　3. Looking at the other side of the object through the glass with water, you will feel the opposite object magnified. It shows that the glass of water at this time is commensurate with a magnifying glass, which can be an erect, magnified virtual image.

Thermal aspect

　　1. In the summer, put a popsicle in a glass and put it in the air for a while, you will find that the outer wall of the glass will "sweating." It shows that the water vapor in the air is cold and liquefied.

　　2, in two identical glasses, each containing hot and cold water, and then drop a few drops of red ink, after a while, you will find that the red ink in the hot cup quickly spread. It shows that the higher the temperature, the faster the diffusion process, and the irregular movement of molecules is fierce.

　　Mechanical aspects

　　1. Take a piece of foam on a horizontal table and place a glass mouth and a glass bottom on the foam. When the glass mouth is placed on the foam, it will be trapped to a greater extent. It shows that when the pressure is constant, the smaller the force area, the more significant the pressure effect and the greater the pressure.

　　2. Fill a glass with water, then cover it with a piece of cardboard, turn it upside down, and you will find that the hard paper will not land and the water will not flow out. Explain the existence of atmospheric pressure.

　　3, filled with rice in a glass, then insert a chopsticks vertically into the rice in the middle of the cup, and squeeze the rice evenly, put a certain amount of water in the cup, after a while, then go When you lift the chopsticks, you will see that the entire cup has also been lifted. It shows that after adding water, the expansion of the rice increases the pressure on the chopsticks, which increases the friction.

　　4. In a container filled with water, put a glass cup that will not only sink to the bottom of the container, but will not sink after placing some stones in the glass. It shows that the "hollow" method is adopted to increase the volume of the drained water and increase the available buoyancy.

　　5, put a glass on the horizontal table, pull it with a spring balance to slide it at a constant speed; then lay the glass on the horizontal table, then use the spring balance to pull it evenly, you will find the spring balance in these two cases The indications are different. It shows that under the same premise, the dynamic friction is less than the sliding friction.

　　6. Put a proper amount of water in a glass, put a piece of cardboard on top of it, and then put an egg on it, quickly force the hard paper to be shot out, and you will find the egg falling into the cup. Inside the water. It shows that the egg has inertia.

Electrical aspects

　　1. Connect the two ends of the small bulb circuit to the bottom of the glass and the bottom of the glass. Close the switch and you will find that the light bulb does not emit light. It shows that the glass is an insulator.

　　2. In the above experiment, if the glass is heated to a red state with an alcohol burner, the bulb will gradually glow. It is stated that there is no clear boundary between the conductor and the insulator.

　　The physicality of the glass seems to be closely related to our life. Understanding these little common sense of the glass not only allows us to review the physics knowledge of middle school for a long time, but also enhances our deeper familiarity with the glass in our daily life.