Mathematics:/uploads/soft/July 2007/2007071719332213770. document

Physics:

First, multiple-choice questions (30 points)

1, the following statement about real image and virtual image is correct ().

Virtual image is the illusion of human beings, while real image is the actual light entering human eyes.

B Virtual image is a shadow, while real image is a bright spot formed by actual light.

C. real images can be presented on the screen, but virtual images can't.

D light will always become a real image after refraction and a virtual image after reflection by a plane mirror.

2, the following instruments, the principle of not using communication device is ().

A boiler water level gauge B cow automatic water feeder C crossing culvert D spring dynamometer

3, according to the group photo, found that some people did not enter the camera, in order to make all personnel into the camera, should take ().

A people don't move, the lens is farther away from people, and the lens retracts.

B people don't move, the camera zooms in, and the camera retracts.

C people don't move, the camera is closer to people, and the camera stretches forward.

D the camera and lens don't move, so people stand closer.

4, the following statement about force is correct ()

An object can produce a force.

B. Any object must be both a force-applying object and a force-bearing object.

There can be no strong interaction between objects without direct contact.

There must be a strong interaction between objects in direct contact.

5, the weight of the following objects close to 1N is ().

A bag of instant noodles B, a student's desk C, a pin D and a brick.

6. One end of the spring scale is pulled by 20N, and the other end is also pulled by 20N, so the reading of the spring scale is ().

Above A 40N B 0N C 20N D is wrong

7, put in the process of air movement, regardless of air resistance, its force is ().

A is only pushed, B is only pushed by gravity, C is pushed, and D is not stressed.

8, about g=9.8N/kg, meaning ().

A 1kg=9.8N B The weight of an object with a mass of 9.8kg1n.

C the gravity of an object is 9.8 times its mass, D the mass is 1kg, and the weight of an object is 9.8 n.

9, in the following examples, increase the beneficial friction is ()

Lubricate the axle of a bicycle. When moving a heavy machine, you often put some wood under it.

The rotating part of the machine has rolling bearings. D the pedal of the bicycle is engraved with convex and concave patterns.

10, wooden blocks on the horizontal ground, which of the following statements is the balance force ()?

The gravity of the block and the pressure of the block on the ground

The gravity of the block and the supporting force of the ground on the block.

C. The pressure of wood blocks on the ground and the supporting force of the ground on the wood blocks

None of the above statements are correct.

1 1, about inertia, the following statement is correct ().

A object has high speed and large inertia; When an object is at rest, it has no inertia.

When the motion state of an object changes, the inertia also changes. All objects have inertia.

12, in the following cases, the way to increase the pressure is ()

A lay sleepers under the tracks of the railway. B widen the schoolbag belt.

C the kitchen knife is blunt, and it is sharper when ground. D. install the crawler on the tractor wheel.

13, we have to keep breathing, and the way of expanding chest and contracting breathing is called chest breathing, in which () can correctly describe the chest breathing action.

A when inhaling, the chest expands and the lung pressure is higher than atmospheric pressure.

B when inhaling, the chest contracts and the lung pressure is lower than atmospheric pressure.

C when exhaling, the chest expands and the lung pressure is higher than atmospheric pressure.

D when exhaling, the chest contracts and the lung pressure is higher than atmospheric pressure.

14, in the design of teapot mouth, which scheme is correct ()

A spout is much higher than B spout, and B spout is much lower than B spout.

C spout is generally as high as spout, and the design above D is unreasonable.

15, when the hospital is infusion for patients, the liquid should be dripped evenly and then injected into blood vessels. In order to keep the whole infusion process dripping at a constant speed, Figure () should be used in the following devices.

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A B C D

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Two. Fill in the blanks (26 points)

16. In the experiment of "studying convex lens imaging", the lighted candles are placed in four different positions of abcd, as shown in the figure. The candles placed in _ _ _ _ _ get the smallest real image, and those placed in _ _ _ _ _ get the upright virtual image. The imaging rule in _ _ _ _ _ is the principle of slide projector.

a b c d

P F

17, the lens of the camera is equivalent to a _ _ _ _ _ _, and the negative is equivalent to _ _ _ _ _ _. To adjust the focal length when taking pictures is to adjust the distance of the lens to _ _ _ _ _.

18, spring dynamometer is a tool for measuring _ _ _ _ _ _, which is made according to the principle of _ _ _ _ _.

19, the crane hangs the goods with the mass of 10t in the air. At this time, the tension of the steel cable on the goods is _ _ _ _. If the crane lifts the goods at a speed of 0.2m/s, the tension of the steel wire rope on the goods is _ _ _ _ _, and the crane lowers the goods at a speed of 0. 1m/s, then the steel wire rope on the goods.

20, according to Newton's first law, when the original static object is not stressed, it will keep _ _ _ _ _ _ _ _; The original moving object will remain _ _ _ _ _ _ when it is not stressed.

2 1. In flood fighting and emergency rescue, a soldier vertically lifted a bag of sandbags weighing 420N with a force of 500N, and the resultant force on the sandbags was _ _ _ _ _ _ _ _.

22. When building a river dam, builders usually make it narrow at the top and wide at the bottom, because the deeper the river goes, The more _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

23. The famous _ _ _ _ _ experiment in history verified the existence of atmospheric pressure. The first experiment to measure atmospheric pressure was _ _ _ _ _ _.

24. An object immersed in a liquid is forced by a liquid, which is called buoyancy, and the direction of buoyancy is always _ _ _.

25. A ship with a displacement of1000t is sailing in this river section, and the ship can only carry cargo and its own * * * weight _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

26, a volume of 0.5 cubic decimeter object, completely immersed in water, buoyancy is _ _ _ _ _, if the weight is 4N, it will _ _ _ _ in water. (float, float or sink)

Iii. Drawing questions (10)

27, complete the following light path

28. Make the following stress diagram.

(1) Push the box with a force level of130 n. ..

(2) Pull the car upward along the slope with a force of 100 N, making an angle of 30 degrees with the horizontal plane. ..

(3) The gravity of a person with a mass of 50kg.

one person

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Fourth, experimental exploration.

29.(6 points) Different convex lenses have different degrees of refraction of light, that is, the focal length of each convex lens is not necessarily the same.

(1) Please guess two factors related to the focal length of convex lens: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

(2) A classmate uses two convex lenses with the same convexity and different cross-sectional areas to converge sunlight, and the length from the convergence point to the optical center is 10cm. It can be inferred from this situation: _ _ _ _ _ _.

(3) A classmate uses two convex lenses with the same cross-sectional area but different convexities to converge sunlight. The length from the convergence point of convex lens to the optical center is 5cm, while the length from the convergence point of plano-convex lens to the optical center is 8cm. Your guess is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

30.(6 points) When students of a physics interest group explore the relationship between the gravity of an object and the mass of the object, the experimental records are as follows:

Measurement object object 1 object 2 object 3

Mass of the object (kg) 0. 1 0.2 0.3

Gravity of an object (n) 0.99 1.96 2.95438+0

Ratio (g/m) 9.9 9.8 9.7

Average value of G/M ratio

(1) During the experiment, the required measuring tools are _ _ _ _ and _ _ _ _.

(2) Fill in the average value of grams/meter in the blank space of the form.

(3) Analyzing the data, the inquiry conclusion is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

3 1, (6 points) The following is the learning process of "studying the influencing factors of sliding friction" conducted by students of a physics interest group. Through experiments, they got the following data:

Contact surface, pressure and friction

1 plank 6 1.2

2 boards 8 1.6

3 sandpaper 8 3.5

(1) In the experiment, to make the indicated value of the spring dynamometer equal to the sliding friction of the wood block, the wood block should be moved under the horizontal tension of the spring dynamometer.

(2) Comparing the data of 1 and 2 twice, the conclusion is: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

(3) By comparing the data of _ _ _ _ _ and _ _ _ _ _, we can see that the rougher the contact surface is, the greater the sliding friction force is under the same pressure.

32.(6 points) The following is an experiment in which students are exploring factors related to buoyancy. During the experiment, the indexes of spring dynamometer are 5N, 4N, 3N and 4N respectively.

Copper sulfate water

Methyl ethyl propyl butyl

(1) Comparing Figure B and Figure C, it can be concluded that buoyancy is related to _ _ _ _ _ _.

(2) Comparing Figure B and Figure D, we can see that buoyancy has nothing to do with _ _ _ _ _ _ _.

(3) To sum up, the conclusion of your inquiry is _ _ _ _ _ _ _ _ _ _ _ _ _ _.

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Verb (abbreviation of verb) calculation problem

33.(4 points) Estimate your own gravity?

34.(6 points) A classmate weighs 35kg and wants to choose an inflatable plastic life buoy (with negligible mass) to learn swimming, so he should choose at least a larger life buoy to ensure that he can float safely on the water when swimming.

2005-2006 school year second semester eighth grade physics final examination paper.

(Beijing Normal University Edition)

(Refer to the answer)

First, multiple choice questions

1、C 2、D 3、A 4、B 5、A 6、C 7、B

8、D 9、D 10、B 1 1、D 12、C 13、D 14、C

15、B

Second, 16, a, d, c, 17, convex lens screen object

18, the tension of the force spring is proportional to the elongation.

19,105n105n105n20, moving in a straight line at constant speed at rest.

2 1, 80N upward 22, Shenda 23, Madeburg Hemisphere

Torricelli 24, upward 25, 107N 107N

Floating 26,5n floating

Three. sketch

4.29. Protrusion degree, cross-sectional area and focal length have nothing to do with cross-sectional area.

The focal length is related to the degree of protrusion.

30. Balance dynamometer 9.8N/kg The gravity of an object is directly proportional to its mass.

3 1, even under the same contact surface, the greater the pressure, the greater the friction.

2 3

32. Density of liquid (type) Depth of immersion in liquid The buoyancy of an object immersed in liquid is related to the density of liquid, but has nothing to do with the depth of immersion in liquid.

33, omitted

34. solution: G=mg=35kg× 10N/kg=350N.

F float =G=pgv.

V=F float /pg

= 350 N /( 103 kg/m3×10 N/kg)

= 0.035 cubic meter

answer

Maybe it's not from Haidian unified examination. ...