This article about the phenomenon of light in the third chapter of second-year physics is specially compiled by kao.com for everyone. I hope it will be helpful to everyone!
1. Fill in the blanks
1. The reason for the formation of shadows is that a shadow puppet show is popular in some areas of our country, which can also be used to explain.
2. When practicing shooting, you need "three points and one line" to shoot accurately, that is, the notch on the scale on the gun, the front sight on the gun and the shooting target must coincide. This is based on the principle.
3. When you enter a dark room at night and turn on the light, the whole room is immediately illuminated by the light, but people do not feel that it takes too long. This is because.
4. Light spreads in The fastest, propagating m per second. A laser signal is sent from the earth to the moon, and the return signal is received after 2.56s. Then the distance from the moon to the earth is m.
2. Multiple choice questions
< p> 5. Which of the following phenomena cannot be explained by the principle of light propagating along a straight line in a uniform medium...( )A. Small hole imaging B. Hand shadow game
C. Phenomenon of solar and lunar eclipses D. Seeing things shaking through fire
6. There is a small square hole on the top of a work shed, and the sunlight falls through it to the ground to form a circular spot. , This phenomenon shows that………………………………………………………………( )
A. The shape of the small hole must be round B .The shape of the sun is round
C. The light spot on the ground is like a small hole D. Light does not propagate in a straight line
7. According to scientists, humans will be If it can be realized, the inhabitants of the moon will be able to see... p> A. Lunar eclipse phenomenon B. Solar eclipse phenomenon
C. Solar and lunar eclipse phenomena D. Invisible solar and lunar eclipse phenomena
3. Experimental research questions
8. In order to explore how light propagates in a straight line, a student found the following equipment: chalk dust, milky white and transparent jelly, Sprite bottle, laser flashlight, small wooden block, small plane mirror, glass of water, foam block, A small metal cylinder, a glass of milk, matches, mosquito coils, etc. Please help him design two plans to explore.
1. Fill in the blanks
1. Light propagates in a uniform substance , if you encounter an opaque object, a shadow will be produced in the area behind the object.
2. When you are lining up and see a person in front of you blocking everyone, the queue will be straightened. This is because of light; when it rains, you always see lightning first and then hear thunder. This is because of. ?
3. The propagation speed of light in vacuum is km/s, and the distance between the sun and the sun is The earth is 1.5 p> 5. We live in the information age, and information spreads at the speed of light in a vacuum, and its speed is m/s; if the transmission distance from Beijing to Nantong City is about 1.5 XlO6m, through the "information highway", Nantong City Receiving information from Beijing requires S.
6. The sunlight passes through the gaps in the dense leaves and forms many shaped spots on the road. This is the sun's rays and is caused by.
2. Choice
7. Shen Kuo of the Northern Song Dynasty recorded the experiment of linear propagation of light and small hole imaging in "Mengxi Bi Tan". He first directly observed the eagle and found that it was flying in the air. , the shadow on the ground also moved, and the direction of movement was consistent with its direction. Then, he opened a small hole in the paper window, so that the shadow of the eagle outside the window appeared on the indoor paper screen. As a result, he observed: "Yuan Dong "The kite from the west reflects the east". After reading the above materials, which of the following statements do you think is wrong ( )
A. The phenomenon of "the kite from the east reflects the west, and the kite from the west reflects the east" It is small hole imaging
B. Shen Kuo observed that "the kite flies in the sky, and the shadow on the ground also moves with it." It is small hole imaging
C Small hole imaging can use light Explanation of straight line propagation
D. When the pinhole is used for imaging, the image moves in the opposite direction to the object moving
8. Among the following statements, the correct one is ( )
< p> A. Light propagates in a straight line B. Light is realC. The propagation of light takes time D. The propagation speed of light is 3X lO8m/s
9 .Cut off the upper part of the can and cover it with translucent paper. Make a small hole in the bottom of the can and use it to do a small hole imaging experiment to observe the object. Which of the following statements is wrong ( )
A. The image is upside down and the object is upside down, and left and right are opposite
B. When the object rotates clockwise, the image rotates counterclockwise
C. The farther the object is, the larger the image will be
D. When the distance between the object and the hole remains unchanged, the greater the distance between the translucent paper and the hole, the larger the image will be.
10. The timekeeper at the end of the 100-meter race must start timing when he sees the white smoke coming from the starting gun, but not when he hears the sound of the gun. This is because
( )
A. Timing is accurate by watching the smoke coming from the gun B. Cannot hear the sound of the gun because of the noise
C. Timing by listening to the sound of the gun is not accurate enough, resulting in lower scores D .None of them are correct
11. In the following media, the propagation speed of light is ( )
A. Air B. Water C. Glass D. Vacuum
12. The following phenomena are not caused by the linear propagation of light ( )
A. The formation of shadows B. The formation of solar and lunar eclipses
C. Chopsticks in water Bent D. Small hole imaging
13. The speed of light propagating in different materials is different. In the following arrangement of light speeds, the correct one is ( )
A.V air >V vacuum>V water>V glass B. V glass< V air< V water< V vacuum
C.V vacuum> V air> V glass> V water D.V glass< V water< V air< V Vacuum
14. On her way home from evening self-study get out of class, Wang Pai discovered that when a pedestrian passed by under a street light, the change of the pedestrian’s shadow should be ( )
A. Gradually change Short B. Gradually becomes longer
C. First becomes longer and then becomes shorter D. First becomes shorter and then becomes longer
3. Calculation and discussion
15. Use a laser transmitter to send a signal to the moon. After sending the signal for the first time, the return signal is received in 2.7 seconds. After some days, the signal is sent out for the second time and the return signal is received in 2.6 seconds. Based on this, please do the math. The moon How many kilometers are the distances between these two locations to the earth?
16. Li Ming wanted to measure the height of a street lamp in the square from the ground. After dinner, the street lamp turned on, and he took a 2.8m The long straight pole and tape measure came to the street lamp with Xiaojun. They walked 7m forward from the lamppost and stood the pole vertically to the ground. Then Xiaojun measured the length of the shadow of the pole, which was 3.5m. Finally, they calculated the height of the street lamp. .You calculate the height of the street light.
1. Fill in the blanks
1. When a flagpole is erected in the sun, the length of the flagpole’s shadow from morning to noon. (Fill in "variable", "unchanged" or "shortened")
2. Use a laser transmitter to send a signal to the moon, and receive the return signal 2.7 seconds after sending the signal for the first time; A few days later, the reflected signal was received after 2.6 seconds after sending the signal again. It can be concluded that the distance between the moon and the earth at these two positions is km.
3. A person with a height of 1.7m stands 1.5m in front of a plane mirror. When he approaches the mirror by 0.5m, the distance from his image in the mirror to the mirror is m, and the height of the image in the mirror is m.
4. There is a river running in the north-south direction. One morning, the sun was very bright. Xiao Ming took his camera to the river to take a photo of the scenery with reflections in the water. To do this, Xiao Ming should stand in the river. the shore.
5. The ancient book "Huainan Wanbi Shu" contains such a passage: "Hang a large mirror high and place a basin under it, and you will see your neighbors." This is the use of principles to observe the surrounding scenery. similar device.
6. A person who is 1.6m tall needs to see his or her full body image in a vertical plane mirror. The length of the mirror must be at least m. If his eyes are 10cm below the head, then the height of the lower end of the mirror from the ground is m.
2. Multiple-choice questions
1. As shown in the picture, when a passerby passes under a streetlight, the length of the shadow formed by the light shining on the person is ( )
A. First become longer and then become shorter
B. First become shorter and then become longer
C. Gradually become longer
D , gradually getting shorter
2. When a partial solar eclipse occurs, we see sunlight shining through the gaps in the leaves under the big tree to form bright spots on the ground. The shape is ( )
< p> A. Round B. Crescent-shapedC. The same shape as the gaps in leaves D. Various irregular shapes
3. As shown in the picture, Cut off the upper part of the can, cover it with semi-permeable paper, make a small hole in the bottom of the can, and use it to do a small hole imaging experiment to observe the object. Which of the following statements is wrong ( )
A. The image and the object are upside down and left and right
B. When the object rotates clockwise, the image rotates counterclockwise
C. The farther the object is, the smaller the image becomes
p>
D. When the distance between the object and the small hole remains constant, the greater the distance between the translucent paper and the small hole, the larger the image will be
4. A person moves on a flat surface at a speed of 1m/s Walking on a straight river bank, he saw his "reflection" in the calm river water moving at a speed of ( )
A. 0 B. 1m/s C. 2m/s D. Can't Confirm
5. Xiao Ming saw from the plane mirror the image of the electronic clock on the opposite side of the mirror as shown in the picture. The time at this time should be ( )
A. 21:10< /p>
B. 10:21
C. 10:51
D. 12:01
6. A mirror hangs vertically on On the wall, the position of the human eye is as shown in the figure. There are three objects A, B, and C placed in front of the mirror. The objects that the human eye can see through the mirror are ( )
A. Only B
B, A and B
C, A and C
D, B and C
7. Children's Paradise Haha, the mirror surface is wavy, which deforms the portrait and makes people laugh. Then ( )
A. The convex part on the surface lengthens the portrait. B. The convex part on the surface shortens the portrait.
p>C. The concave part on the surface lengthens the portrait. D. The concave part on the surface shortens the portrait.
IV. Experimental questions, calculations, and drawing questions
1. As shown in Figure 1, place a lit candle on a horizontal table and look at the candlelight through three pieces of cardboard with small holes drilled. When it is pressed, we can see the candlelight, which means: .
2. (2000? Xi'an City, Shaanxi Province) In front of the provincial government office building in Xincheng Square, the five-star red flag was flying on the flagpole. In order to measure the height of the flagpole, the students designed three plans, as shown in the picture As shown in 2, please choose one of the options.
(1) Explain the physics knowledge used;
(2) Use the students’ measured data to calculate the height of the flagpole.
3. When a student was doing the "Characteristics of Plane Mirror Imaging" experiment, he put a glass plate vertically on top of the same ruler, and then took two candles A and B of equal length in front of it. Place it vertically on the ruler, light the candle A in front of the glass, and observe with your eyes, as shown in the figure. In the above experiment:
(1) The function of the ruler is to facilitate comparison of images. relationship with objects;
(2) Two candles of equal length are to compare the relationship with objects;
(3) Remove candle B and place it at its location If a light screen is placed on the light screen (fill in "can" or "cannot") the light screen will receive the image of candle A, which means that the image of the candle is an image.
4. Draw the image of the letter "F" in the plane mirror in the picture below.
5. Based on the image A′B′ formed by object AB in the mirror, draw the position of the plane mirror in the picture.