Key words: Physics permeates all fields of human life, around which physicists and students have scientific consciousness and scientific learning methods.
As an important branch of natural science, physical science not only plays an important role in promoting the progress of material civilization and deepening human understanding of nature, but also has an indispensable influence on the development of human thinking. From natural philosophy in Aristotle's time to classical mechanics in Newton's time, and then to relativity and quantum mechanics in modern physics, all these are tangible manifestations of physicists' scientific quality, scientific spirit and scientific thinking. With the development of science and technology and the progress of society, physics has penetrated into all fields of human life. For example, just looking for optical knowledge in the car has the following points:
1. The rearview mirror outside the driver's cab is convex.
By using the divergent function of convex mirror to light and the characteristics of upright, narrow and virtual image, the objects you see are small and the observation range is wider, thus ensuring driving safety.
2. The reflector of automobile headlights is a concave mirror.
It is made by using the property that concave mirror can reflect the light from the light source placed at its focus into parallel light.
Car headlights should always be equipped with glass lampshades with horizontal and vertical stripes.
Car headlights consists of a light bulb, a reflector and a front glass cover. According to the knowledge of lens and prism, car headlights glass cover is equivalent to the combination of lens and prism. When driving at night, drivers should not only see the road ahead, but also see the fixers, road signs, forks and so on. The lens and prism refract the light, so the lampshade diffuses the light to the required direction according to the actual needs, so that the light illuminates the road in front of the car and the roadside scenery evenly and softly. At the same time, this astigmatism lampshade can slightly refract some light to illuminate road signs and milestones, thus ensuring driving safety.
After the car is fitted with brown glass, it is difficult for pedestrians to see the faces of people in the car.
The tawny glass can reflect some light and absorb some light, so the light penetrating into the car is very weak. In order to see the passenger's face clearly, it is necessary to reflect enough light from the face and transmit it to the outside of the glass. Because the light inside the car is weak and there is not enough light to transmit, it is difficult to see the passenger's face clearly.
Except buses, the front windows of most cars are inclined.
When the front window glass of a car is tilted, the image of the passenger in the car reflected by the glass is in front of the country, and pedestrians on the road can't appear in the air above, so the image of the passenger in the car is separated from the pedestrians on the road, and the driver won't have an illusion. The front window of a bus is much higher than that of a car. Even the vertically installed front window looks the same height as the window, and pedestrians on the road cannot appear at this height, so drivers will not confuse the image of passengers outside the window with pedestrians on the road.
Another example is as follows:
Spiced tea eggs are very popular with people, especially when it is hot. Careful people will find that when the eggs are just taken out of the boiling gravy, if they are eager to shell and eat them, it is inevitable to peel them off with the "meat". To solve this problem, there is a trick, that is, soak the eggs just out of the pot in cold water for a while, and then peel them, so that the eggshells can be peeled easily.
General substances (with a few exceptions) have the characteristics of thermal expansion and cold contraction. However, when different substances are heated or cooled, the speed and amplitude of expansion and contraction are different. Generally speaking, substances with low density are easier to expand and contract than substances with high density, and substances with fast heat transfer are easier to expand and contract than substances with slow heat transfer. An egg consists of a hard shell, a soft protein and a yolk, and their expansion and contraction are different. When the temperature changes slightly or slowly and evenly, nothing can be displayed; Once the temperature changes sharply