1. The speed of a normal moving object is about 5m/s, which may be ().

A. Snail pedestrians, bicycles and cars

2. Noise is an environmental pollution. Some cities stipulate that motor vehicles around schools are forbidden to honk their horns. The following methods to reduce noise are the same as ().

A. install sound insulation equipment in the recording studio B. plant flowers and trees in schools or residential areas.

C. construction at night is prohibited on the construction site. D. People who work in noisy factories should wear earmuffs.

3. People standing in front of a flat mirror, when he approached the flat mirror, what happened is ().

A the size of the image remains unchanged, and the distance from the image to the mirror becomes smaller. B the image size and the distance from the image to the mirror remain unchanged.

C. As the image becomes larger, the distance from the image to the mirror becomes larger. D. As the image becomes larger, the distance from the image to the mirror becomes smaller.

The picture shows light passing through a lens (not shown). Belong to the convex lens is ()

5. Which of the following statements about some common temperatures in the living environment do you think is the most practical ()?

A. The flame temperature of the match is 37℃. B. The room temperature that makes people feel warm and comfortable is 23℃.

C. The normal body temperature is 47℃. The lowest temperature in our calendar is 0℃

6. The picture shows an ordinary thermometer. Of the following statements about thermometers, the correct one is ()

A. its indicator is 8℃ B. Its dividing value is 1℃

C. it can't be read without the measured object. It is made according to the law that liquid expands when heated and contracts when cooled.

7. As shown in the figure, when the rocket flies in the atmosphere, the head rubs and heats up, and the temperature can reach several thousand degrees Celsius. Coating a special material on the rocket and melting and vaporizing at high temperature can protect the rocket head, because ().

A. both melting and vaporization release heat. B. Melting absorbs heat and vaporizing releases heat.

C. both melting and vaporization absorb heat. D. Melting releases heat and vaporizing absorbs heat.

8. Regarding quality, the following statement is true ()

A. water becomes ice and its mass becomes smaller. Astronauts have great mass on earth, but little mass in space.

C. Iron blocks are forged into blocks after heating, and the mass becomes smaller. D 1kg cotton and1kg iron have the same mass.

9. After reading the table below, Liu Tong Jr. learned some conclusions, of which the correct one is ().

Density/kg of some substances? m-3

Water 1.0× 10 3 mercury 13.6× 10 3

Ice 0.9× 10 3 pine 0.5× 10 3

Kerosene 0.8× 10 3 copper 8.9× 10 3

Alcohol 0.8× 10 3 lead 1 1.3× 10 3

A. different substances must have different densities.

The density of solids is higher than that of liquids.

C solid copper block and solid lead block with equal mass, the volume of copper block is smaller than that of lead block.

The same substance has different densities in different states.

10. There is a layer of snow with uniform thickness on the flat ground. Xiao Ming stepped down hard to form a concave footprint, as shown in the figure. The snow under the footprints, squeezed by external forces, can be approximately regarded as ice. Using the density of ice, we can estimate the density of snow by measuring which of the following physical quantities? ( )

A. Snow thickness and footprint depth

C. Ice thickness and footprint D. Depth and footprint

Second, fill in the blanks (65438+ 0 points for each blank, * * * 20 points)

1 1. Put some broken foam in the paper basin of the speaker. When the speaker sounds, the phenomenon as shown in the figure will appear. This phenomenon shows that the sound is caused by objects, and the sound from speakers can be heard, indicating that the sound can spread indoors.

12. The doctor gave the pregnant woman a B-ultrasound, which showed that sound waves could spread; Doctors use ultrasonic waves to break stones in the human body, which shows that sound waves can spread.

13. Xiao Ming knocked on the same drum face twice with different strength, and the sound was different. Xiaoli adjusts the tightness of violin strings mainly to change the sound. Different musical instruments make different sounds.

14. As shown in the figure, the morning sun rays obliquely hit a horizontally placed flat mirror, and the reflection angle is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

15. The solar eclipse is caused by _ _ _ _ of light; Standing by a calm pond, you can see the reflection of trees on the shore and the fish swimming in the water. The former is the _ _ _ _ _ _ phenomenon of light, and the latter is _ _ _ _ _ _ _ _ _ (fill in "real image" or "virtual image").

16. A few tourists leave empty pure water bottles on the mountain when they play, which not only pollutes the environment, but also may cause forest fires. This is because when it rains, the pure water bottle is filled with water, which is equivalent to a _ _ _ lens. Strong sunlight on sunny days will have a _ _ _ effect on the light, which may cause the dead leaves to catch fire. So we play in the mountains.

17. During the take-off of the deck of China's "Liaoning" aircraft carrier, the pilot was right with the seat on the plane as the reference. Taking the deck as a reference, the pilot was right.

18. One method of artificial rainfall is that the plane scatters dry ice (solid carbon dioxide) at high altitude. Dry ice enters the clouds and quickly turns into gas, absorbing a lot of heat from the surrounding, so the water vapor at high altitude becomes small ice crystals or water droplets, which increases the number of ice crystals and water droplets in the clouds, thus forming rainfall. (Name of filling status change)

Third, the experimental questions (2 points per grid, 34 points * * *)

19.( 10) When exploring the imaging law of convex lens, Xiao Zhang made the following inquiry. Please answer:

(1) In the experiment, as shown in the figure, in order to make the image in the center of the screen, the screen should be adjusted to _ _ _ _ _ _ _ _ (optional "up" and "down").

(2) The focal length of the convex lens is known as 10cm. Place the candle flame at a distance of 25cm from the convex lens, and adjust the light screen to get the real image of the inverted head, _ _ _ _ _ (zoom in, zoom out and equal in size can be selected). The instrument that can be made by applying this principle is _ _ _ _ _ _ _.

(3) On the basis of the experiment in (2) above, if the position of the convex lens is kept unchanged and the position of the candle and the light screen are reversed, the image on the light screen will be inverted, _ _ _ _ _ _ _ (optional "enlargement", "reduction" and "equal size"), and the instrument that can be made by applying this principle is _ _ _ _ _ _.

20.( 12) Xiao Ming guessed that adding other substances to water would definitely affect the freezing point of water. In order to test this conjecture, he put some salt in the water, put the brine in a container and put it in the refrigerator to study the solidification process of the brine. Every once in a while, Xiao Ming observes the state of brine to measure the temperature, and draws the temperature data recorded in the solidification process into a solidification image as shown in figure A.

(1) It can be seen from the image that the salt water solidification process took _ _ minutes, and it was _ _ state when it was cooled to the fifth minute.

(2) Careful observation of the image shows that the temperature of the material before solidification is lower than that after solidification.

_ (choose "Fast" or "Slow").

(3) The freezing point of salt water is Celsius. The experiment verified Xiao Ming's conjecture, because the freezing point of salt water has changed compared with water. (Select "High" or "Low").

(4) If a test tube filled with ice-water mixture is put into the molten salt water mixture shown in Figure B, the ice in the ice-water mixture in the test tube will be _ _ _ _ (select "more", "less" and "unchanged").

2 1.( 12 minutes) Xiaoming measured the density of the stone with a tray balance and a measuring cylinder. The experimental steps are as follows:

A tie the stone with a thin thread, gently put it into the water of a measuring cylinder, and measure the total volume of water and stone.

B. calculate the density of the stone.

C. pour a proper amount of water into the measuring cylinder and measure the volume v of water.

D. weigh the mass m of this stone with a balance.

(1) The correct order of the above experimental steps is.

(2) When adjusting the balance of the balance beam, it is found that the pointer is still in the position shown in Figure A, and the balance nut should be screwed to

(Fill in "left" or "right") adjustment.

(3) Xiao Ming measured the quality of the stone with the adjusted balance. As shown in Figure B, please point out two mistakes in Xiaoming's operation.

(4) After correcting the error, when the balance is balanced, the mass of the weight in the right plate and the position of the wandering code on the balance are represented by C, and the mass of the stone is g. He measured the volume of the stone by the method shown in Figure D, and the density of the stone is

Gram/cubic centimeter.

IV. Calculation questions (4 points for 22 questions, 6 points for 23 questions, 6 points for 24 questions, * * * 16 points)

22.(4 points) During the National Day, the Xiao Qiang family traveled to Laibin City by car. When they approached Laibin City, they saw a roadside sign as shown in the figure. After that, the car passed a 600m-m-long section at a constant speed within 1 minute. Q:

(1) The speed of the car passing through this section; (2 points)

(2) Please indicate whether the car is speeding in this section according to the calculation results; ( 1)

(3) Please write a warning to remind drivers and friends to drive safely according to traffic laws. ( 1)

23.(6 points) In order to save energy and reduce emissions, hollow bricks are widely used to replace solid bricks in buildings. As shown in the figure, a hollow brick with a mass of 3.6kg has a specification of 20cm× 15cm× 10cm, and the solid part of the brick accounts for 60% of the total volume.

Q: (1) What is the density of brick material? (3 points) (2) How many kilograms of materials can be saved by producing each hollow brick compared with solid bricks of the same specification? (3 points)

24.(6 points) "Five? During the Golden Week, Lele and her mother traveled to Wuxi and bought a teapot in Yixing, as shown in the picture. She heard that Yixing teapot is made of Yixing's unique clay material, and wanted to know the density of this material. So she measured the mass of the lid with a balance of 44.4g, and then put the lid into a beaker filled with water, and measured the mass of the spilled water as14.8 g.

(1) Would you please help Lele calculate the density of this material? (3 points)

(2) If the measured mass of the whole empty teapot is 159g, what is the volume of materials used in the teapot? (3 points)

Reference answer

1.C 2。 C 3。 A 4。 C 5。 B 6。 D 7。 C 8。 D 9。 D 10。 A

1 1. vibrating air 12. Information; Energy 13. Loudness timbre 14.60? decrease

15. Linear propagation; Reflection; Refraction; Virtual image 16. Convex convergence 17. the static movement

18. Sublimation, Sublimation and Liquefaction

19 or less. (1).(2) Zoom out, camera. (3) Magnification, slide projector (or projector).

20.( 1) 10; Liquid; (2) fast; (3)-2; Low; (4) More

2 1.( 1) DCAB (2) Right (3) Take the weight directly by hand. The position of the object and weight is reversed (4) 52 2.6.

22.( 1) 36 km/h (2) The car did not exceed the speed limit in this section (3) The answer is reasonable.

Test analysis:

(1) The speed of cars passing through this section: v = s/t = 600m/60s =10m/s = 36km/h;

(2) According to the data on the bulletin board, the speed limit of this journey is 60 km/h > 36 km/h, so the car is not speeding;

23.( 1)(2)2.4 kg

Test and analysis: (1) The hollow part has volume but no mass, so the mass of the solid part is: m 1=3.6kg,

The total volume of brick v = 20cm×15cm×10cm = 3000cm3 = 3x10-3m3,

The solid part of the brick accounts for 60% of the total volume.

∴ The volume of the solid part is: V 1=60%? v = 60%×3× 10-3 m3 = 1.8× 10-3 m3，

Material density

Answer: The density of this brick is 2× 103kg/m3. /m3。

(2) The mass of solid bricks with the same specification is: m = ρ V = 2×103kg/m3× 3×10-3m3 = 6kg,

The materials that can be saved are: m2 = m-m1= 6kg-3.6kg = 2.4kg. 。

Answer: Compared with solid bricks of the same specification, each hollow brick can save 2.4 kilograms of materials.

24.( 1) V cover =V water =m water/ρ water =14.8g/(1.0g/cm3) =14.8cm3.

ρ mud =m cover /V cover =44.4g/ 14.8cm3=3.0g/cm3 (or 3.0x103kg/m3).

⑵V pot =m pot/ρ mud = 159g/(3.0g/cm3)=53cm3 (or 5.3x 10-5m3).