1. Fill-in-the-blanks: There are 10 small questions, with each blank 1 point and ***22 points. Please fill in the answer on the horizontal line of the question.

1. The mass of an egg is about g; The blackboard used in your classroom is about 100 meter long.

2. The nucleus consists of protons and protons. If the diameter of an atom is 10- 10 meter, then the diameter of carbon nanotubes manufactured by scientists in China is 33 nanometers, which is equivalent to the length of each atom arrangement. (1 nm = 10-9 m)

3.65438 June+10/October 65438+9: 00 on February 2005, the Shenzhou VI manned spacecraft was successfully launched, and China realized a multi-day flight for two people for the first time. . The spacecraft was stationary relative to _ _ _ _ _ before it left the rocket. During the return process, the spacecraft's return capsule collided violently with the atmosphere, and the mechanical energy was transformed into a fireball.

4. The electrified coil of the motor rotates in the magnetic field, realizing the direction conversion.

2. Multiple choice questions: 10 questions, with 2 points for each question and * * 20 points. Of the four options given in each question, only one is correct. Please put the code before the correct option in brackets after the question.

1. The voltage value of domestic circuits in China is ().

A. 1.5V B.36V C.220V D.380V

2. China's Ministry of Public Security requires motorists and front passengers to wear seat belts on their chests, mainly to reduce the harm that may be caused by one of the following situations ().

A. reverse the car B. the speed is too slow

C. Sudden start D. Emergency braking

3. In the process of the following state changes, the sublimation phenomenon is ()

A. incandescent bulbs that are used for a long time will turn black.

B. the wet soil in the flowerpot has dried up.

C. Small water drops appear on the outer wall of the cup for cold drinks in summer.

D. In autumn, the tiles on the roof are frosted.

4. The following phenomenon, belongs to the phenomenon of light reflection is ().

A. observing biological specimens with a magnifying glass

B.you can see your own image in the flat mirror.

C. Show your shadow under the street lamp at night.

D. the coins sunk at the bottom of the washbasin look very shallow.

5. In the following cases, can reduce the pressure is ().

A. The blades of knives, axes and scissors are very thin.

B in order to insert the straw into the soft package beverage box, one end of the straw is cut very sharply by the quilt.

C. make the bag strap wider

D. cut wet and soft soap with thin wire.

6. The following phenomenon, does not belong to the proliferation phenomenon is ()

A. When perfume is sprinkled on clothes, you can smell the fragrance.

B. oil droplets are scattered on the water.

C. When sugar is put into water, the water becomes sweet.

D chalk is written on the blackboard, and the longer it takes, the harder it is to erase it.

7. Immerse the iron block in water for the first time and in kerosene for the second time. Comparing the buoyancy of iron in two liquids, the correct one is ().

A. when iron blocks sink into water, they will be subjected to great buoyancy.

B, iron blocks are immersed in kerosene, which has great buoyancy.

C. the buoyancy of two iron blocks is the same.

D. it is impossible to compare the buoyancy of these two iron blocks.

8. In a physics activity class, the students are discussing "If we lose …". The following are the representative views put forward by four students. What do you think is right ()?

A. If there is no friction, nothing is static.

B. If all conductors lose resistance, all electrical appliances will not work normally.

If gravity is lost, the balance can no longer be used to measure the mass of an object.

If the magnetic field around the magnet disappears, there will be no electricity in the world.

9. A classmate took a physics textbook for Grade Three that fell to the ground to the desktop. In this process, the size of his works in textbooks is the closest ()

A.0.3 J B.3 J C.30J D.300 J

no

Even those with pictures can't get up.