w88top mobile:w88top,mobile,Shandong,Distric:? Shandong District, Jinan City, Shandong Province, 2016-2017 school year, eighth grade, semester, final exam, semester exam, physical exam questions, download, Zhangqiu District, Jinan City, Shandong Province, 2016-2017 school year, eighth
Shandong District, Jinan City, Shandong Province, 2016-2017 school year, eighth grade, semester, final exam, semester exam, physical exam questions, download, Zhangqiu District, Jinan City, Shandong Province, 2016-2017 school year, eighth grade, end of the next semester The physics exam of the district entrance examination 2016-2017 school year end of the next semester district entrance examination eight grade physical exam questions (out of 100 points; time 60 minutes) volume I (multiple choice questions 49 points) one, single-choice questions (each question is given Among the four options, only one of the options meets the requirements of the topic. For each sub-question, 3 points are counted and 33 points. Multiple choices, wrong choices, no selections are not scored. As shown in the horizontal snow, the total mass of Fangfang wearing a sled is 70Kg, and it is not caught in the snow; while the total mass of Xiaoming wearing sports shoes is 50Kg, but it is deep in the snow. The following statement is correct? A. Fangfang’s pressure on the snow is smaller than that of Xiaoming? B. Fang Fang’s pressure on the snow is the same as Xiao Ming’s? C. Is the pressure of Fangfang on the snow smaller than that of Xiaoming? D. The area and pressure of the force are not equal, and it is impossible to compare who is strong against the snow. As shown in the figure, in the process of investigating the characteristics of liquid pressure, the metal box of the micro-pressure gauge is placed in the water. The following method can reduce the difference in the height of the liquid level on both sides of the U-tube of the pressure gauge? Move the metal box of the pressure gauge up a distance? B. Move the metal box of the pressure gauge down a distance? C. Turn the metal box of the pressure gauge 180° in the original position? D. Place the metal box of the pressure gauge in the same depth of salt water. Regarding the atmospheric pressure, what is correct in the following statements? A. The atmospheric pressure is generated by the gravity of the atmosphere, so its direction is always vertical downwards? B. The higher the ground, the smaller the atmospheric pressure, so the pressure in the plateau is lower than that in the plain? The location and altitude of the same location are unchanged, so the atmospheric pressure is constant? D. Air is also a fluid, so the thickness of the atmosphere can also be calculated using the formula p = ρgh. The students of the science and technology team used the 3D printer to make four models, which were fixed on the bracket and placed on the electronic scale. As shown in the figure, the hair dryer was horizontally blown from the right to the left with the same gear, and the electronic scale showed What may be significantly reduced is A. A B. B C. C D. D. In the extracurricular experiment, put the eggs in the cup of water, the eggs sink to the bottom of the cup, as shown in Figure A; add salt to the cup and stir until the eggs are suspended, as shown in Figure B, in the process? The density of the liquid in the cup is constant B. The weight of the egg becomes smaller? C. The buoyancy of the egg becomes larger. The bottom of the container is exposed to the pressure of the liquid. As shown in the figure, there are two identical fish tanks A and B on the horizontal table. There is a proper amount of water. After putting a plasticine boat into the B, the boat is floating, and the water in the two fish tanks is just right. Leveling. Then put them on the scale, then the scale of the scale? A. When the A is placed on the big B. When is B placed on the big? C. A and B are placed as big as D. Unable to judge. When people swim, they often feel that when they slowly walk into the water, the body seems to slowly become lighter.
Please ask a scientific question that is valuable and easy to explore based on this phenomenon? A. People are buoyant in the water, so they will feel the body lighter? B. What is the relationship between the size of the human body's buoyancy and the depth of entering the water? ?C. What are the factors related to the buoyancy of an object? ?D. What is the relationship between the size of the object being buoyant and the volume immersed in the liquid? . As shown in the figure, the lever is in equilibrium and the scale is even, and the quality of each hook code is equal. If a hook of the same quality is added to the hook code on both sides of the lever, the lever will be A. Sink at the left end. Sink at the right end C. Still balancing D. Unable to judge. An experimental group uses the two pulley blocks A and B (each weighing the same weight) to lift the same weight at the same speed and raise the same height. Regardless of the weight and friction, the following statements are correct? A. A map is more labor-saving, the mechanical efficiency of the two maps is the same? B. A map is more labor-saving and mechanically efficient? C. The figure B is more labor-saving, and the mechanical efficiency of the two figures is the same? D. The figure B is more labor-saving and mechanically efficient. A sprinkler that travels at a constant speed on a level road is sprinkling water. For the sprinkler, the following statement is correct? A. The mechanical energy is constant and the gravitational potential energy is constant. The mechanical energy becomes smaller and the kinetic energy becomes smaller. C. The mechanical energy is unchanged and the kinetic energy is reduced. The mechanical energy is small and the kinetic energy is unchanged. Since Thomson discovered electrons, people began to study the internal structure of atoms. Scientists have proposed many models of atomic structures. In the first half of the 20th century, the most accepted atomic structure is in the figure. Tomato B. Watermelon C. Bread D. Solar system two, multiple choices (each of the four options given, at least two options meet the requirements of the topic, 4 points per question, 16 points. Partially selected and no mistakes, 2 points, wrong choice Do not choose not to score). As shown in the figure, the experiment related to pressure knowledge, in which the analysis is incorrect is ?? In the A picture experiment, the Pascal cracking barrel experiment proves that the liquid pressure decreases with the increase of depth? B. In the experiment of B, the table with the weight is placed on the fine sand. The lighter the weight, the deeper the table legs are. C. In the C-picture experiment, the tensile force and the area of ??the piston when the syringe piston is pulled at a constant speed are measured, and the value of the atmospheric pressure can be estimated. Dingtu experiment, in the classroom can use water instead of mercury to do the Tori split experiment. As shown in Figure a, b, c three solid small balls, where a and b are equal in mass, b and c are the same volume; when three small balls are placed in the water, the ball is floating, the b ball is suspended, and the c ball is sunken. bottom. Then the correct one in the following judgment is? A. Their volume relationship in water is: Va < VbVc? B. Their gravity relationship is GaGb>Gc?C. Their density relationship is: a
17.2 points When the cylinder shown in the figure is immersed in a liquid, its side is subjected to the pressure of the liquid in each direction, and the lower surface is subjected to the upward pressure of the liquid than the upper surface is subjected to the downward pressure of the liquid. This is why objects immersed in liquids are buoyant.
18.2 points are the commonly used dovetail clips of the students, AB=BC. When the force is clamped to point C to open the clip, the point can be regarded as a fulcrum. At this time, the clip can be approximated as a lever (optional) “Effortless”, “labor” or “equal arm”). 19.2 After the research of scientists, we know that atoms can be subdivided. That is, an atom is composed of a nucleus and a nucleus composed of neutrons. Fourth, drawing (3 points for each question, 6 points) 20. As shown in the figure, the cup is placed on the inclined surface. Please draw a schematic diagram of the pressure of the cup on the inclined surface. twenty one. In the lever shown in the figure, O is the fulcrum. Please draw the force arms L1 and L2 of the forces F1 and F2 in the figure. V. Short answer (4 points) 22. When I was sleeping, lying on the bed of 'Si Mengsi', I felt more comfortable than lying on a hard bed. What is the reason? 6. Comprehensive analysis and calculation questions (16 points). Large cities have amazing lengths of underground drainage pipes and a large number of drainage pumping stations. Once blocked, it will cause a lot of hazards. Divers are often required to complete this dangerous work. A diver weighs 70kg, puts on a 10kg wetsuit, and then hangs 25kg of metal weight, about the volume. Please calculate and analyze (g take 10N/kg): If the sole area of ??each diving shoe is 300cm2, before the launching, the diver walks on the road and the pressure on the road is how much the diver sneaked into the deep water of the drainage pumping station. What is the buoyancy? The station pool is 6m deep, the diver is tall, and the pressure of the water on the top of the diver's helmet at this position is 24. With the acceleration of urban construction, high-rise residential buildings have risen. However, the urban water supply can only meet 16 floors. The 6th floor or above needs to use the water pump for secondary pressurization. The water is first stored in the roof water tank, and then the whole building is supplied with water. If the pump sends 6m3 of water to the 20m high roof tank, the time is 10min. Take g=10N/kg. Answer by calculation: the mass of water with a volume of 6m3; the work done by the pump on the water; the power of the pump. Seven, experimental exploration (17 points) 25. Min Xiaomin used the device as a device to explore the 'characteristics of the internal pressure of the liquid' (the same liquid is contained in the B and C containers). In the experiment, first of all, it is necessary to check whether the pressure gauge can be used normally. If the rubber film of the probe is lightly pressed or pressed with a finger, it is found that the height difference of the liquid column on both sides of the U-shaped tube is small, indicating that the pressure gauge is small. Air tightness (optional 'good' or 'poor'); after adjusting the pressure gauge, the liquid level on both sides of the U-shaped tube is level. Xiaomin immersed the probes into the two liquids (water or alcohol, respectively) in Figure A and Figure B, and found that the height difference between the liquid columns on both sides of the U-tube in Figure A is smaller than that of Figure B. Conclusion The pressure inside the liquid is related to the density of the liquid. His conclusion is (optional 'correct' or 'wrong'); ______________ (if his conclusion is correct, fill this 'A' solution is water or alcohol; if His conclusion is wrong, please fill in the reason for the error). Then he changed the depth of the probe in Figure B, and its investigation is shown in Figure C. Comparing the graphs, the deeper the depth of the probe immersed in the liquid, the greater the height difference between the liquid columns on both sides of the U-shaped tube, indicating that the pressure of the liquid here is greater. Xiaomin also found that in the same kind of liquid, when the depth of the probe is the same, only the direction of the probe is changed, and the height difference of the liquid column on both sides of the U-shaped tube does not change, indicating. 26. When the 'exploration of the size of buoyancy is related to what factors', the students put forward the following conjecture: ?A. May be related to the depth of the object immersed in the liquid; ?B. May be related to the density of the object; C. May be related to the volume of the object; ?D. May be related to the volume of the object immersed in the liquid; E. May be related to the gravity of the object. In order to verify the above conjecture, Xiao Ming used the following equipment to do the experiment as shown in the figure. Equipment: equal-sized iron, copper, spring dynamometer, a glass of water, a glass of salt water, a string. Analyze and compare experiment 34, you can verify that the guess is correct; analyze and compare experiment 45, you can verify that the guess is wrong (optional 'A', 'B', 'C', 'D' or 'E'); analysis and comparison experiment And, it can be verified that the guess B is wrong; the analysis and comparison experiment 67 can be obtained: the size of the buoyancy of the object immersed in the liquid is related; after completing the above investigation, Xiao Ming has selected different liquids and conducted several experiments. Its purpose is to (optional letter number). ?A. Looking for universal law B. Take the average to reduce the error. 27. As shown on the left, the experiment is to explore 'what factors are related to the size of the kinetic energy of the object'. The experimental steps are as follows: ?I. Let the same steel ball roll off from the height at different heights on the slope and observe the distance the wood block moves after being hit. II. Let the steel balls of different qualities roll off from the same height from the slope, and observe the distance moved by the block after being hit. Answer the following questions: (1) Step I is to study the relationship between the magnitude of kinetic energy. (2) Step II is to study the relationship between the magnitude of kinetic energy. (3) The magnitude of the kinetic energy of the steel ball in this experiment is reflected by observing the comparison of the wood blocks. (4) If the water level is absolutely smooth, this experiment will (optional 'can' or 'can't') for the purpose of inquiry. (5) Some students improved the experimental device to the right of the figure, using the iron balls of different quality to compress the spring to the same extent and hit the same block. Is the experimental plan feasible? A: If he operates according to this plan, he will see the phenomenon: Eighth grade physical reference answer Volume I (multiple choice questions 49 points) First, single choice question two, multiple choice questions Volume II (non-choice questions total 51 points) Third, fill in the blank (1 point per empty, 8 points) 16.< < 17. Balanced 18. B. Arm 19. Electron proton 4. Drawing (3 points for each question, 6 points) 5. Short answer (4 points) 22. Answer: Lying on the bed of Simmons Compared with lying on a hard board bed, the contact area between the body and the bed is large, and the body-to-bed pressure must be according to the formula P=. When the pressure is constant, the force area becomes larger and the pressure is smaller, so it will feel more comfortable. Sixth, analysis and calculation of comprehensive questions (16 points) 23. Solution: ? (1) m total = 70kg + 10kg + 25kg = 105kg? G = mg = 105kg × 10N / kg = × 103N? F = G = × 103N? S = 300cm2 = ? p = F /S=×103N/=×105Pa;?(2) Because of immersion, V row=?F float=ρ water gV row=×103kg/m3×10N/kg×=8×102N?F pressure=G-F float= 4×105N-3×105N=1×105N?(3)h==?p”=ρ water gh=×103kg/m3×10N/kg×=×104Pa.24. Solution: (1) can be obtained by ρ=m/V, m=ρV=×103kg/m3×6m3=6×103kg; (2) Gravity of water: G=mg=6×103kg×10N/kg=6×104N, the work done by the pump on water:?W= Gh=6×104N×20m=×106J;?(3) The time used is t=10min=600s, the power of the pump in this process: P=W/t=×106J/600s=2000W. 7. Experimental exploration (17 points) 25 (1) Difference (2) error does not guarantee the same depth (3) B and C (4) At the same depth of the same liquid, the pressure inside the liquid is equal in all directions. 26. (1) D A (2) 12 56 (3) Density (4) A 27. (1) Velocity (2) Mass (3) on the horizontal plane The size of the moving distance.
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