1. A group of stranded whales were found on the beach in southern Australia, and local residents mobilized urgently to help the whales return to the sea. They roughly calculated with a tape measure that the volume of a whale is about 3 m3, so the mass of this whale is about ().
A, 3×102kg b, 3×103kg c, 3×104kg d, 3×105kg.
2. When medical staff measure the patient's temperature with a thermometer, the mercury in the thermometer remains unchanged during the measurement ().
A, mass b, volume c, density d, temperature
The density of human body is similar to that of water. The following is Xiao Yi's estimate of his figure, and the correct one is ().
A, Xiaoyi's mass is about 500 kg B, and Xiaoyi's height is about 1.65x 103cm.
C xiaoyi weighs about 50 N D and its volume is about 5× 10-2 m3.
4. When writing with essays, the friction between the pen tip and the paper belongs to rolling friction ()
A, ballpoint pen b, writing brush c, pencil d, pen
5. The following objects only have gravitational potential energy ().
A. A stone B is placed on a high mountain, a taut string C, a ball D rolling on the horizontal ground, and a compressed spring.
6. In 2003, China launched Shenzhou 5 manned spacecraft, which was in a state of "weightlessness" during normal flight in orbit. In this environment, which of the following experiments cannot be carried out normally ()?
A, measure the length of the book with a scale B, observe the onion skin with a microscope.
C, change the light path d with a plane mirror, and measure the gravity of the object with a spring dynamometer.
7. Although the chess pieces placed vertically on the magnetic Go board are subjected to vertical downward gravity, they will not fall off. The main reason is ().
A, attracted by Weiqi disk B, attracted by Weiqi disk C, attracted by Weiqi disk D, and attracted by Weiqi disk sliding friction.
8. In the following phenomena, the motion state of the object has not changed ().
A, a small train moving at a uniform speed along a circular track on a horizontal table; B, start the car and drive out of the station.
C. Parachutes fall from the air at a constant speed D. In the autumn wind, leaves fall to the ground.
9. As the saying goes, "It takes two hands to make a sound" reflects physical knowledge ()
A, slap can't vibrate, so you can't make a sound. B, an object can't produce force.
C, sound is produced by force D, only two objects contact will produce force.
10. Concrete is compressive, not tensile, while steel bars have tensile effect, but the compressive effect is poor. As shown in the figure, it is a concrete precast slab for building. In the picture, the upper surface of the board is A, the lower surface is B, and there is a steel skeleton near B. So, when laying the floor, it should be ()
A, A face up B, B face up C, which face is the same D, which face looks up at the floor.
1 1. In the following example, it is () that increases the beneficial friction.
A, when pushing heavy objects, the roller is often padded. B, tourist soles are engraved with uneven patterns.
C. The bottom of the sled is very smooth. D. Lubricate the bearings of the machine.
12. Regarding the concept of force, the following statement is true ().
A, there must be no force between objects that are not in contact with each other. B the stressed object cannot be the application object.
C, between objects in contact with each other, there must be a powerful role. D, without objects, there will be no powerful role.
13. When one person smokes in a public place, others will "smoke passively". Smoking is generally forbidden in public places because ().
A, if a person smokes, others envy him and smoke with him. B. Smokers' smoke diffuses in the surrounding space, and smoke molecules in the air keep moving.
C, smoke molecules remain static, people take the initiative to inhale smoke. D. Passive smoking is because smoke molecules are relatively large and people are easy to inhale into the lungs.
14. It is usually said that "iron is heavier than wood", but the following statement is wrong ().
A, the same volume of iron and wood, iron mass is big, iron mass is bigger than wood.
C. Compared with wood blocks, iron blocks with the same mass are smaller and denser than wood blocks.
15. Regarding the spring dynamometer, the following statement is correct ().
A, on the moon, it is impossible to measure force with a spring dynamometer. B the letter "n" on the spring dynamometer is used to indicate its model.
C, when measuring, there should be no friction between the spring and the shell. D each cell of the spring dynamometer used in the laboratory represents 0. 1kg.
Fill in the blanks (18× 1 = 18)
16. The milk packaging bag of "Double Happiness" is marked with the words "net content of 220mL(227g)", and the density of milk is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
17. The instructions of the spring tensioner say: spring tension 10cm required 10 N. A classmate stretched the tensioner shown in the figure by 0.4 m, and his pulling force was _ _ _ _ _ _ _ _ _ _ _ _ _.
18. The same plasticine is kneaded into a ball first. If its gravity is 0.5 N, then it is kneaded into a rabbit, and its gravity is _ _ _ _ _ _ _ _ N, which shows that the gravity of an object has nothing to do with its _ _ _ _ _ _ _ _ _.
19. As shown in the picture, the athletes are jumping on the pole vault, which contains some physical principles, such as:
(1) The column bends under the action of force, which means that the action of force can be _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
(2) The athlete is pulled up by the pole while exerting force, which means _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
Scientists can see the spectrum of a galaxy by observing its light with instruments. In the 1920s, astronomer Hubble discovered that the spectrum of galaxies moved in the direction of _ _ _ _ _ _ _ (i.e. "long wave" or "short wave"), which indicated that galaxies were in _ _ _ _ _ _ (i.e. "approaching us" and "leaving us").
2 1. The specific heat capacity of water C water = _ _ _ _ _ _ _ _ _ _ _ _, and its physical meaning is _ _ _ _ _ _ _ _ _ _. A city is a famous fishing city in China, and B city is the main cotton producing area in China. These two cities happen to be.
At the same latitude, the average annual sunshine amount is basically the same, so curve A represents _ _ _ _ _ _ _ _ _ _ _. (A/B).
22. Different substances are made up of different molecules. The content of the molecular model includes the following three points, namely:
( 1)__________________________________。 (2) Molecules are always in endless motion.
(3)__________________________________。
23. Immerse the metal block into the glass containing alcohol, and 10 g alcohol overflows from the glass. If the metal block is immersed in a beaker filled with water, the mass of water overflowing from the cup is _ _ _ _ _ _ _ _ _ _ g(ρ alcohol = 0.8× 103 kg/m3).
24. Some details in life are often overlooked, such as dripping water if the faucet is not tightened. Suppose a faucet drops 2 drops per second because it is not tightened, each drop is about 0.005 ml. According to this calculation, this faucet will lose about _ _ _ _ _ _ g of water if it drips continuously for one day. According to the current water fee standard in Suzhou, a ton of water costs 2.40 yuan, while Suzhou has a population of about 6 million. If each person saves a glass of water (200 mL) every day, the total water fee that can be saved in one month (30 days) is about _ _ _ _ _ _ _.
Three. Drawing questions (2 points for each picture, * * * 8 points)
25. Complete the mapping according to the following requirements:
The schematic diagram of (1) force is as shown in Figure ①: 3N gravity of an object placed on a horizontal workbench;
(2) The schematic diagram of force is used to draw the gravity and friction of the block resting on the inclined plane in Figure (2);
(3) Schematic diagram of force Figure ③ shows the gravity and tension of the ball hanging on the vertical wall;
(4) Schematic diagram of force. Draw the force of football flying in the air in Figure 4. (ignoring air resistance)
4. Experimental design questions (each grid 1 point, 2 points for drawing in 27 questions, *** 14 points)
26. In order to determine the density of soy sauce, Xiao Ming designed the following experimental data record table, in which the total mass of the initial beaker and soy sauce has been recorded. The left picture shows the total mass of the beaker and the remaining soy sauce after he poured some soy sauce into the measuring cylinder, and the right picture shows the volume of soy sauce poured into the measuring cylinder from the beaker. Please help Xiao Ming fill in the experimental data sheet according to the situation shown in the picture.
Total mass of beaker and soy sauce m Total mass of beaker and remaining soy sauce /g
Total mass m 1/g pour soy sauce quality.
M2/ g volume of soy sauce poured out
Density of V/cm3 soy sauce
ρ/g？ Cm -3
150
27. An extracurricular interest group filled plastic buckets with four different liquids of known density, measured their gravity with a spring dynamometer, and recorded the data in the table below:
(1) As shown in Figure A, Xiao Ting found that there is a certain rule between the liquid density and the reading of the spring dynamometer by analyzing this table, and the image that can correctly reflect this rule is _ _ _ _ _ _ _ _. (Fill in "A", "B" or "C")
(2) If the liquid with unknown density is filled in the keg, the indicated value of the spring dynamometer is 2.3 N, and Xiao Ting calculates the density of the liquid as _ _ _ _ _ _ _ _ _ _ _ kg/m3.
(3) According to Xiao Ting's discovery, Xiao Jiang converted the spring dynamometer and bucket used in the experiment into a liquid densimeter. When in use, the density of the liquid can be directly read out from the position pointed by the pointer of the spring dynamometer just by filling the small barrel with the liquid to be measured. Please help her mark the zero scale and the maximum scale of the liquid densimeter and their corresponding density values beside the scale on the right side of Figure B.
28. When a physics study group explored the relationship between the gravity of an object and the mass of the object, the experimental records were as follows:
Average value (N/kg) of the g/n ratio (G/m, N/kg) of the mass m/kg of the measured object.
Object l 0. 1 0.99 9.9
Object 2 0.2 1.96 9.8
Object 3 0.3 2.9 1 9.7
(1) In the inquiry process, the required measuring tool is _ _ _ _ _ _ _ _ _.
(2) Fill in the average value of the ratio g/m in the blank of the above table.
(3) By analyzing the experimental data in the table, the conclusion is: _ _ _ _ _ _ _ _ _ _ _.
29. The composition and main properties of several commonly used alloys are listed in the right table. According to the information provided in this table, do you think the material of electric furnace wire should be _ _ _ _ _ _ _ _ _ alloy (fill in the name of alloy).
5. Calculation problem (6 points for the 30th question, 5 points for 3 1 question, * * *1point)
30. In order to judge whether an iron ball is hollow or not, students of extracurricular physics interest group measured the following data:
The mass of the iron ball m/g The original volume of water in the measuring cylinder V/mL After the iron ball is put in, the total volume of water and iron ball V/mL.
79 50.0 70.0
(1) Is the iron ball hollow or solid by calculation?
(2) If the iron ball is hollow, what is the volume of the hollow part?
(3) If the hollow part is filled with mercury, how many kilograms of mercury is needed?
(ρ water = 103 kg/m3, ρ iron =7.9× 103 kg/m3, ρ mercury = 13.6× 103 kg/m3).
3 1. Xiaohua's family has a pile of rice with a volume of 4.5m3 in the grain drying field. In order to estimate the quality of this pile of rice, he put a bucket of rice in an empty bucket and measured the rice quality in the bucket as 10 kg, and then put a bucket of water, and measured the water quality in the bucket as 9 kg. So, how many tons is the total mass of this pile of rice?
6. Physics inquiry questions (questions 32-34 1, 35-6, *** 19)
32. Xiaojun observed the moon through a high-powered telescope, and found that the surface of the moon was uneven, as shown in Figure A, because when a meteor was running in space near the moon, it fell to the surface of the moon under the action of the moon's gravity and collided with the surface of the moon to form a crater, which was called a lunar crater. Xiaojun guessed that the depth of the lunar crater may be related to the mass, volume and falling height of the meteor. So, he designed a simulation experiment to explore the depth of the moon pit with a plate covered with thick fine sand and several different balls and scales, as shown in Figure B. After the experiment, the data are recorded in the following table:
Please analyze the experimental data and answer the following questions: (1) According to the data of 1, 2 and 3, the depth of the "moon pit" is related to the _ _ _ _ of the meteor.
(2) According to the data of _ _ _ _ _ _ _ _ _ _ _
(3) The depth of the "Moon Pit" is also related to the volume of the meteor: the larger the volume, the deeper the "Moon Pit". (Fill in "shallow" or "deep")
(4) Please combine Xiaojun's research process and put forward another conjecture on the issue of "factors affecting the depth of the moon pit": _ _ _ _ _ _.
33. Bicycle is a very familiar means of transportation, as shown in the picture. Judging from the structure and use of bicycles, it involves a lot of knowledge about friction. For example: a. There are patterns on the tires; B, the wheel is made into a circle; C, adding lubricating oil to the rotating part; D. the pedal is uneven; E. squeeze the brake hard when braking; F. the shaft is provided with balls; There is a groove in the handlebar of this car.
(1) Among the above contents (only fill in the letters before each option): The ones that increase the friction by changing the roughness of the contact surface are: _ _ _ _ _ _ _ _; By increasing the pressure to increase the friction is: _ _ _ _ _ _ _ _; Changing sliding into rolling to reduce friction is: _ _ _ _ _ _ _ _ _ _ _.
(2) When the pedal is pressed hard to make the bicycle move forward, the direction of friction between the rear wheel and the ground is _ _ _ (select "front" or "rear").
(3) Please use your imagination boldly: "If there is no friction, what will happen to the bicycle?"? Write two reasonable scenes:
①_____________________________; ②_______________________________。
Xiaoying, 34.4 years old, has a little pain in her ears and needs to take paracetamol syrup or drops (syrup and drops have the same effect), but only paracetamol drops are available at home. For a 4-year-old child, the safe dose of syrup is 6 ml. Then taking _ _ _ _ _ _ _ ml of drops is equivalent to taking 6 ml of syrup.
Every 5 ml contains
Paracetamol 250 mg
safe dose
1~6 months 0.3mL
7 ~10.6 ml in February
1.9 ml for 3 ~ 24 months.
No more than 3 times the dosage per day.
Each 5mL syrup contains
Paracetamol125mg
safe dose
2~4 years old 6 ml
5~6 years old 8mL
7~8 years old 10mL
No more than 3 times the dosage per day.
35. In order to protect the environment and control soil erosion, the school's environmental protection team designed and conducted a study on river sediment concentration.
The first stage is theoretical analysis: ρ water, ρ sand and ρ muddy water represent the density of water, sediment and sediment water respectively, and X represents the quality of sediment contained in each cubic meter of sediment water (called sediment concentration), and the relationship between ρ muddy water and ρ water, ρ sand and X is deduced; Then, the image of sediment water density ρ changing with sediment concentration x is made.
The second stage is experimental verification: put a certain amount of dry loess into the measuring cylinder, then pour a certain amount of clear water, calculate the sediment concentration X, and measure the density of sediment water ρ mud water; Then, clear water is added for many times to prepare sediment water with different densities, and the same calculation and measurement are carried out to obtain multiple groups of ρ mud water and X data; Then, according to these data, a ρ mud-X image is made to show the relationship between the density of sediment water and the concentration of sediment. They were surprised to find that the experimental results were consistent with the theoretical analysis.
The third stage is the actual measurement: a flash flood washed the ground, and they collected 40 L water samples with a total mass of 40.56 kg. The previously measured dry sediment density is ρ sand =2.4× 103 kg/m3, so the average sediment concentration in the flood is calculated.
(1) Please take part in the work of the first stage of the environmental protection team, deduce the relationship between ρ mud and ρ water, ρ sand and x, and then draw the ρ mud -X coordinate diagram of the image of sediment water ρ mud density changing with sediment concentration x according to the relationship.
(2) Please take part in the calculation in the third stage of the group and work out the average sediment concentration in the flood (write the necessary formulas and steps).
__________________________________________________________________________________
Proofreading: Senior Two Physics Preparation Group.
Mid-term exam answers
Physics in the second grade of junior high school
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
1. Multiple choice questions (15×2=30 points) BADAA DBCBA BDBBC
Fill in the blanks (1× 18)
Every cubic meter16.1.03x103,1.03x103kg, and the quality of a cubic meter of milk is1.03x103kg. 17. 160;
18.0.5, shape; 19. The deformation of an object and the action of force are mutual; 20. Long wave, leaving us;
2 1. 4. 2× 103 Joule/(kg.℃), the heat absorbed or released when the temperature of one kilogram of water rises or falls by one degree Celsius is 4.2× 103J, b;
22, the object is composed of a large number of molecules, there is a gap between molecules _, there is attraction and repulsion between molecules; 23. 12.5; 24.864、86400。
Three. Drawing questions (2 points for each picture, * * * 8 points) are omitted.
4. Experimental design questions (each grid 1 point, 2 points for drawing in 27 questions, *** 14 points)
26. 1 17、33、30、 1. 1 27.( 1)B； (2) 1.5× 103 ; (3) Omission
28.( 1) pallet scale and spring dynamometer; (2)9.8; (3) The gravity of an object is directly proportional to its mass.
29. Nickel-chromium alloy, high-speed tool steel.
5. Calculation problem (6 points for the 30th question, 5 points for 3 1 question, * * *1point)
30.( 1) Hollow (2)10cm3 (3)136G31.5t.
6. Physics inquiry questions (questions 32-34 1, 35-6, *** 19)
32.( 1) falling height; (2)3、6、7; (3) shallow; (4) conjecture: ellipsis
33.( 1) Answer. e .h, F, B.G; (2) before; (3)① Omission; 2 ellipsis. 34.3。
35.( 1) If the sediment concentration is X, the mass of sand is xV, the volume of sand is, and the volume of water is:
The mass of water is:, and the total mass of water and sand is: ... 2 minutes.
Density of sediment water: = =
Then order. .................. 1 min.
The density of sediment water varies with the sediment concentration x, as shown in answer sheet 3. ............................................................................................................................................................
(2) Basis: then x =.................... 1 min.
Known rho sand = 2.4× 103kg/m3.
Kg/m3
So k = x = kg/m3 ...............1min.
I solemnly promise to abide by the principle of good faith in the examination, consciously restrain and standardize my words and deeds, and strictly abide by the examination discipline.
Mid-term exam answer sheet
Physics in the second grade of junior high school
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
A multiple-choice question (15×2=30 points)
The title is12345678 91012131415.
answer
Fill in the blanks (1× 18)
16.____________、__________________ 、_____________________________________;
17._________________________________; 18._______________、________________;
19._______________、________________; 20._______________、________________;
2 1._______________、_________________________________________、____________;
22、_________________________________、_____________________________________;
23.________________________________; 24.________________、________________。
Three. Drawing questions (2 points for each picture, * * * 8 points)
25.( 1) (2)
(3) (4)
4. Experimental design questions (each grid 1 point, 2 points for drawing in 27 questions, *** 14 points)
26.____________、_____________、_____________、_____________
27.( 1)______________________; (2)______________________ ; (3)
28.( 1)________________、________________ ; (2)__________;
(3)___________________________________________________。
29.___________________________、__________________________。
5. Calculation problem (6 points for the 30th question, 5 points for 3 1 question, * * *1point)
30.
3 1.