Scientific literacy physics test questions
Proposer: Gao examiner: Li Keshun.
◆ Note to candidates:
1. Full score of this volume 130, examination time 100 minutes;
Please fill in the answer in the corresponding position on the answer sheet. The answers on the test paper are invalid and will not be scored.
A, multiple-choice questions (this question *** 14, each 4 points, ***56 points. Only one of the four options given in each question is correct. )
1, a hydrogen balloon is tied with a very small weight, and the weight only moves in a straight line at a uniform speed under the action of gravity and rope tension, regardless of the influence of air resistance and wind. The direction of the uniform motion of the weight is the direction of the dotted line shown by the arrow in the figure, and the correct position of the balloon and the weight G in motion is ().
2, about the center of gravity of the object, the following statement is correct ().
A the center of gravity of any object must be on this object.
B, the center of gravity is the heaviest point on the object.
C the center of gravity of an object with a regular shape may not be in the center of the object.
D, the position of the center of gravity of the object will change with the change of the shape of the object.
As the picture shows, the actors are performing acrobatics. It can be estimated from the picture that he threw an egg.
In this process, the work done on eggs is the closest ()
A, 0.3 Joule B, 3 Joule C, 30 Joule D, 300 Joule
4. An airplane moves in a straight line at a constant speed to the left in the horizontal direction, and gently releases a ball from the airplane every 1 second. If the influence of air resistance and wind force is not considered, when three balls land, people standing on the ground will see which of the three balls is arranged in the air ().
As shown in the picture, two children, A and B, are standing on the horizontal ground, playing hand in hand and competing for strength. As a result, a pulled b over. Regarding the relationship between the forces acting on both sides in this process, the following statement is correct ().
A, the force of both parties must be greater than that of Party B.
B, A's pull on B and B's pull on A is a pair of balancing forces.
The strength of Party C, Party A and Party B must be equal.
D, only in the process of A pulling B, the force of A is greater than that of B, and in the possible short-term stalemate,
These two forces are equal.
6. As shown in the figure, it is a simulation diagram of lightning between clouds. In the figure, A and B are two Lei Yun, and the charges are in the south and north directions respectively. In the process of discharge, a discharge channel is formed between two cloud tips. It is found that the N pole of the small magnetic needle located directly above the channel turns into the paper and the S pole turns out of the paper. The following statement is correct ().
A, A and B have the same charge, and B and A are positively charged.
C and B are positively charged. D. In the process of discharge, the amount of charge is converted into internal energy and light energy.
7. As shown in the figure, a wooden block A is placed on a long wooden board B, and one end of the spring scale is connected to A, and the other end is fixed on the wall. The long board b is placed on the level ground. Under the action of constant force F, the long board B moves at a uniform speed, and the pointer of the horizontal spring scale is T. The following statement about friction is correct ().
A, the friction on the block is equal to F.
B, the friction on the long plate is equal to T.
C, if the long board moves at a speed of 2 nu, the friction force on the long board is equal to 2F.
D, if the force of 2F acts on the long board, the friction force acting on the wood block is still equal to T.
8. As shown in the figure, when the conveyor belt with rough surface is stationary, it takes t for the slider to slide from the top end A to the bottom end B of the conveyor belt, then ()
When the belt moves counterclockwise, the time for the slider to slide from point A to point B must be greater than t..
When the belt moves counterclockwise, the time for the slider to slide from point A to point B must be equal to t.
C, when the belt moves clockwise, the time for the slider to slide from A to B must be equal to T.
D, when the belt moves clockwise, the time for the slider to slide from A to B must be longer than T.
9. The same piece of wood can just stay underwater under the action of objects B and C twice, as shown in the figure, so the following statement is wrong ().
A, in both cases, buoyancy must be equal.
The quality of B and B is definitely greater than that of C.
The mass of c and b must be less than that of a.
The density of d and b must be greater than that of a.
10. In the container shown in the figure, A and B each have a light piston that can move freely, with water under the piston and air above it. The atmospheric pressure is constant, the bottoms of A and B are connected by pipes with valves K, and the whole device has no heat exchange with the outside. At first, the water level in A is higher than that in B. Open the valve to make the water in A gradually flow to B, and finally reach a balance. In this process ()
A atmospheric pressure does work on water, and the internal energy of water increases.
B, water overcomes atmospheric pressure to do work, and the internal energy of water is reduced.
C, atmospheric pressure does not do work on water, and the internal energy of water remains unchanged.
D, atmospheric pressure does not do work on water, but the internal energy of water increases.
1 1. In the circuit shown in the figure, if ab is the input terminal, the access voltage is 20V, AB is the output terminal, and the slider of the sliding rheostat with total resistance value R is placed in the center of the rheostat, then the following statement is wrong ().
A. when there is no load connection, the output voltage UAB= 10V.
B. When AB is indirectly connected to a load with a resistance value of R, the output voltage UAB.
The greater the indirect load resistance of C and AB, the closer UAB is to 10V.
When the indirect load resistance of D and AB is large, UAB may be greater than 10V [Source: Science | Network].
12. A physical projector has 10 identical strong light L 1 ~ L 10 (24V/200W) and 10 identical indicator light x1~ x1.
The power of a, X 1 decreases and the power of L 1 increases.
B, X 1 power increases, L 1 power increases.
C, X2 power increases, and other indicator lights decrease.
The power of D and X2 decreases, and the power of other indicator lights increases.
13, there is an object in front of the convex lens, which can be refracted by the convex lens to form a reduced image on the screen. If the object is shortened at the speed υ in the direction perpendicular to the main optical axis (the length of the object is not zero), then ()
A, in the process of shortening the object, the image is also shortened at the speed of nu.
B, in the process of shortening, the image is shortened at a speed less than υ.
C, in the process of shortening, the image becomes higher at a speed greater than υ.
D, in the process of shortening, the image becomes higher at a speed less than υ.
14 As shown in the figure, the AC surfaces of two identical glass right-angle prisms ABC are placed in parallel with some uniform transparent medium in the middle. The monochromatic beamlet O is incident perpendicular to the AB plane and in the reflected light ().
Any one of a, 1, 2 and 3 (parallel to each other) is possible.
Any one of B, 7, 8 and 9 (parallel to each other) is possible.
C, can only be one of 4 and 6 (parallel to each other)
Any one of d, 4, 5 and 6 (parallel to each other) is possible.
Fill in the blanks (this item is ***5 small questions, with 4 points for each small question and 20 points for * * *. ) [Source: Subject Network ZXXK]
15.20℃ has enough cold water and 70℃ has enough hot water. In order to make 200 kilograms of warm water at 50℃, _ _ _ _ _ kilograms of cold water at 20℃ and _ _ _ _ _ kilograms of hot water at 70℃ (excluding heat loss) are needed.
16. As shown in the figure, when the pulley block is studied, the weight of the object A is measured to be 6N. When dynamometer A is pulled to the right at a constant speed of 0.2m/s, the indicators of dynamometer A and dynamometer B are 1.0N and 2.4N respectively. Then the power for pulling dynamometer _ _ _ _ _ _ _ _ _ _ _ W, and the extra work for pulling dynamometer A at a constant speed is _ _ _ _ _ _ _ _ J.
17, and the volume of water passing through a certain section in unit time is called water flow. At present, a water pump pumps the water to a height of 2 m, the outlet water flow is 0.6 m3/s, the pump efficiency is 75%, and the pump power _ _ _ _ _ _ _ _ _ W (the density of water is 1.0× 103 kg/m3, g).
18. Support the midpoint of a 2m-long massless flat plate on a low fulcrum on the horizontal plane, and put two balls on the flat plate, as shown in the figure. It is known that M A =3kg is located in the middle of the chessboard and M B =2kg is located at the right end of the chessboard. Now let the balls A and B move to the left along the chessboard at the speed of 0.2m/s and 0. 1m/s respectively, and start to rotate after passing through the _ _ _ _ _ _ _ s flat plate.
19. In the circuit shown in the figure, it is known that R1= 6Ω, R2 = 3ω and R3 = 4Ω, so the ratio of the actual power of these three resistors after the switch is closed is _ _ _ _ _ _ _ _ _ _ _ _ _ _.
Iii. Experiment and inquiry questions (this item is ***2 small questions, 20 small questions with 6 points, 2 1 small questions 10 points, *** 16 points. )
20. The greater the tension of the spring, the greater the elongation of the spring. A classmate added a hook code under the vertically suspended spring to explore the relationship between the tension and elongation of the spring. The data in the table is the experimental data recorded by this classmate within the elastic limit of the spring. (g= 10N/kg)
Hook code quality m/g 0 30 60 90 120 150
Total spring length l/cm 6.07.28.49.810.812.0.
(1) According to the experimental data, make a diagram of the relationship between the pulling force F and the spring elongation X in the coordinate system as shown in the figure (the spring elongation is equal to the total length minus the length of the spring when it is not hooked);
(2) When the length of the spring is 8cm, the hook code quality at the lower end of the spring is _ _ _ _ _ _ _ _ _ g.
2 1, the actual power supply has a certain resistance, such as dry battery, which we need to describe by its voltage u and resistance R. In the actual calculation process, it can be regarded as an ideal power supply with a voltage of U, a resistance of 0 and a series resistance of R, as shown in Figure A. There is a power supply in the laboratory, with a power supply voltage of about 3V and a resistance of less than 1ω. In order to measure the voltage and resistance of power supply, there are two ammeters, the resistance R1=15Ω, R2 = 5ω, and the measuring range is 0.3A The following two measuring circuits are designed: B and C.
(1) Please select a feasible measuring circuit: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
(2) Briefly describe the experimental steps: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
_________________________________________________________________________;
(3) According to the measured data and known quantities, the power supply voltage U = _ _ _ _ _ _ _ _ _ _ _ _ and the internal resistance R = _ _ _ _ _ _.
Fourth, the calculation problem (this item is ***3 small questions, the 22nd question 12 points, the 23rd question 13 points, the 24th question 13 points, the first ***38 points. The answer must have the necessary formula and solving process, and only the final answer can't be scored. )
22. As shown in the figure, a solid cylinder with a height of 2m and a diameter of 0.02m2 is lifted from underwater at a uniform speed by pulley block, and the cylinder density is 2.5× 103kg/m3. If the maximum tensile force that the rope around the pulley can bear is 400N, regardless of friction and the mass of the pulley and rope. If the rope end moves downward in a straight line at a uniform speed of 0.2m/s under the action of the pulling force f, the water level change is not considered. (g= 10N/kg, and the density of water is 1.0× 103 kg/m3);
(1) How high is the upper surface of the cylinder above the water, and the rope is broken?
(2) How long does it take from the time when the upper surface of the cylinder touches the water surface to the time when the rope is broken?
23. "Maritime Joint -20 12" Sino-Russian joint military exercise was held in the Yellow Sea near Qingdao from April 22 to 27 on 20 12. Suppose a torpedo speedboat is chasing an enemy ship running away on the same line ahead at a speed of 30m/s during the exercise. When the distance between them is L=2km, a torpedo is launched, and the torpedo advances at a speed of 60m/s in the water. T 1=50s later, the captain saw the fire from the torpedo hitting the enemy ship through the telescope, and found that the damaged enemy ship was still escaping, so he immediately gave the second attack order, and the second torpedo advanced at the same speed. After t2=30s, the torpedo hit the enemy ship again and took it down. (regardless of the time of light propagation)
(1) What was the escape speed of the enemy ship before the first torpedo hit it?
(2) What was the escape speed of the enemy ship before the second torpedo hit?
24. The rated voltage of the two appliances is 6V, and the rated current is 0. 1A and 0.3A respectively.
(1) Connect these two appliances in parallel in a circuit with a voltage of 8V. To make them work normally, how many resistors should be added, how to connect them (draw a circuit diagram to calculate), and what is the power of the resistors at least?
(2) If they are connected in series to the 12V circuit, what can be done to make them all work normally (draw the circuit diagram and calculate the instructions)? And calculates the total power of the circuit.