Chapter 11 Colorful Material World?

Section 1 Universe and Micro-world?

1. solid state; Liquid state; Gaseous 2. D 3。 D 4。 B 5。 A six. C 7。 B 8 is big; The molecular arrangement has changed 9. 10- 10? m 10 . a 1 1 . a 12。 Proton; Neutron 13. Nucleus; Extranuclear electrons 14. Similar: all revolve around the nucleus; Difference: Planets basically rotate on a plane 15. When water freezes, its volume will increase by 16. Molecule 17. It can be transparent or opaque. Solid and liquid?

Quality in the second quarter?

1 . kg； kg； Balance 2. Left; Add 3.d4.b5 Left 6.56× 106? ; 0.056 7.34 128. the weight of the object; 66.8 9. Shape, state and position

10.B 1 1。 C 12。 C 13。 a 14.8 1.4； Constant 15. Horizontal platform; Zero scale line; Balance nut 16. Take out the one with the smallest weight in the right disk, and then move the travel code 17. Omit 18. Omit 19. A little?

Density in the third quarter?

1. 1.0× 103? kg/m3？ ; 1m3？ Water quality 1.0× 103? Kg 2。 Constant; Become bigger; Decrease by 3.50; 5× 104? 4. volume; Density; Quality 5. Smaller; Constant; Smaller 6.c7.c8.c9.d10.a1.c12.b13.d?

14.？ v？ =14.7m× 2.9m×1m = 42.6m3.

∵? =m？ /? V

∴? M= 0？ Hey? =2.8× 103? kg/m3？ ×42.6m3？ = 1. 19× 105? kg？

15. According to the density formula? =m/V？ The volume of 200 grams of alcohol is 250 cubic centimeters. , measuring 250cm3 with a measuring cylinder? Alcohol, the mass is 200g g g.

16. Measure their mass with a balance. The biggest quality is salt water, and the smallest is alcohol, because? Hey? ┭ huh & gt Hey? ┱?? & gt ┚ Eye-eye? Sniff? Difficult to hum? ⒄ ?? 5. Accordingly, the quality of salt water is the largest, and the quality of alcohol is the smallest. 17. Omit?

Section 4 Measuring the density of matter?

1.4.6; 0.92× 103? kg/m3？ 2.53.4; 20; 2 .67 3.7; Not four. Left; 3.67 5.B 6。 ④; Take back the minimum weight and move the moving code to balance the beam. 7.b, too large, because when the liquid in the beaker is poured into the measuring cylinder, a small amount of water remains on the beaker wall, which makes the measured volume smaller. Therefore, the measurement result will be too large. 8.200 times; 1.2× 103? Kg 9。 Omit 10. ( 1)8.9g/cm3？ ; (2) copper; (3) 16. 1g- 1.8g = 14.3g 1。 (1) Step 1, the midstream code should be adjusted to the far left of the ruler. The second step is not to adjust the balance nut to balance the balance beam, but to add and subtract the weight. ② No, the density of metal? What =m? 1×? /(m3-m4+m 1)？

Section 5 Density and Social Life?

1.4℃; Small; Big 2. Little three. Ceramics 4.a5.c6.a7.bcd8.c

9. Omit 10. The quality of iron is great; The density of iron is high, and the mass of iron is 1 1 when the volume is the same. When the alcohol lamp is lit, the heating density of cold air around the alcohol lamp decreases and increases, and the cold air next to it flows and supplements, and the air convection forms wind, so the windmill will rotate. 12. The density of water is the highest at 4℃, so the temperature is low in winter, and the water will float on the surface after freezing, but the underwater temperature will not be too low, so fish can swim freely. 13. Generally installed under the house. The rise of hot air can quickly raise the temperature of the whole room.

14. 1428 block 15.0.2kg, 3× 10-4? m3？ 16.？ ┡D phthalein = (? m？ 1? -? m？ 0? )? ┧? /(? m？ 2? -? m？ 1? )?

17.18. (1)10g, (2)4.4 cubic centimeters.

Unit test?

1. unchanged; A bigger 2. Solid state; Gaseous state; Liquid 3. 0.2? 4. 1584.2m3？ 5.C6。 A7.B8.B9.A 10。 A 1 1。 C 12。 D 13。 (1) Your code is not placed on the left zero line. (2) The desktop is not horizontal and the right side is biased. After the experiment, the experimental equipment was not sorted out 15. ( 1) 175.6; (2)70; (3)2.5; Small 16. (1) as shown in the table?

Drainage hole diameter? d？ /cm 1.52.03.0 5.0

Is it time to drain? t？ /s73.04 1.2 18.46.8

(2) The smaller one is shown in Figure (3)?

(4)? T and d? 2? Inverse ratio can be done? t？ And [SX(] 1[]? D2 [SX]] and observe whether this line is a straight line.

17.( 1)30; (2)0.027; Polypropylene 18. Mistakes; Mistakes; The density of table tennis is smaller than that of rice; Separate objects of different densities (as long as examples and other statements conform to this principle)

19. Yes. The method is to weigh the total mass of this pile of needles with a balance, then weigh the mass of 20 needles, and find out the mass of one needle, so that the total number of needles in this pile can be calculated. The actual number of needles is different from that calculated, because the quality of needles cannot be exactly the same, and the measurement itself cannot make them exactly the same because of the accuracy of the balance. 20. thinking correctly; I can't tell because the volume of A is 12.09cm3? The volume of b is 12.06cm3? The volume difference of AB is 0.03cm3? , far less than the dividing value of the measuring cylinder, the eyes can't see it.

The volume of 2 1.0.5kg wine is 625cm3? ; The volume of 0.5kg soy sauce is 442.5cm3? ; Xiao Pang made a mistake. ?

Chapter 12 Movement and Force?

What is the first section description of the movement?

1. Relativity 2. Earth axis; Sun 3. Mechanical movement 4. A moving ship; Due west on Highway 5. Still; Exercise 6. Ground; Exercise 7. Helicopter; Move down; Move down 8. Shore; Running water 9. Ship; Shaanxi 10. B 1 1。 Omit 12. The illusion arises because the opposite train is regarded as a reference object, and Baiyun and Heshan Lake are regarded as reference objects. Draw houses, trees and white clouds on the narrow cardboard, draw two horizontal lines under the wide card to represent the road, draw a car on the road, and then open a seam on both sides of the upper part of the wide paper to make the narrow paper just pass through. Pull the paper left and right to observe the phenomenon of 65438+ 15.24 h; ; Because the time of the earth's rotation is 24h 16, it means that the height relative to the sea level is 17. Handover, two people try to be relatively still 18.

What is the movement speed in the second quarter?

1. speed; M/s; Kilometers per hour 2. Constant speed and straight route. 3. the object moves 4. 1m/s 5. Height; 6. The distance traveled in the same time is shorter; Time taken to drive the same distance; The distance traveled per unit time is 7.3m/s; 4m/s； [SX(] 10[]3[SX)] m/s 8.3000m9. C 10。 B

1 1.( 1)60km/h； 30min (2)11:30-13: 0012.95.4km/h13. Omit 14. Tip: Tap once at one end of the steel pipe with a hammer, observe at the other end, and record the tapping sound from the sight. T, with s=vt? Calculate the length of steel pipe 15. 16. 1? h=5t？ 2? (2)? 1.4 1s？ 17. Yes; The reason is omitted 18. T35 times; ? 1 10.4? Kilometers per hour?

Section 3 Length, Time and Its Measurement?

1. Omit 2. Omit 3.m；; Kilometers; s 4. 1× 10-4？ ; 0. 1 5. 150~ 170; Praseodymium minimum 6. (1) Keep your eyes on the scale; (2) The ruler should be at the edge of the measured object; (3) The scale should not be tilted by 7.6 [sx (] 4 [] 5 [sx]]; 6; [SX(]4[]5[SX)] 8。 BDAC 9。 C 10。 A

1 1.b 12. omitted 13. omitted14.1ms =10-3? Seconds; 1 femtosecond = 1× 10- 15? Seconds 15. 16. The data 17.8cm is incorrect. Operation or observation reading error during measurement 17. Tip: Use a thin cotton thread to pave the railway line from Beijing to Guangzhou according to the route in the atlas, then straighten it, measure the length of the cotton thread with a scale, and then separate it with a scale. Scheme omitted 18. (1) balance is still necessary; Measure the time required for the ball to swing 10 or more times, and then find out the time required for swinging once; (2) Make the ball swing at a certain angle, respectively change the cycloidal length of the ball, and measure the time required for the ball to swing once; (3) Conclusion: The period of the ball swing is related to the length of the line, but has nothing to do with the swing angle and the mass of the ball?

Section 4 Force?

1. Motion state; Shape change II. The thrust of water; Mutual 3. Newton; Cattle; N 4。 Increase the resistance (install a parachute) and move at a faster speed. 5. Door handle; Action point 6.c7.1; Change the motion state of an object. D 9。 D 10。 D 1 1。 Omit 12.

13. Change the motion state of the object; Right; The action of force is mutual; Rocket; There is a vacuum on the moon and no air (14. 15). The forces between objects are interactive (16), (3); Change of shape; (2),(4); Movement state change 17. (1) action time; (2) Omit 18. According to the reciprocity of the force on the object, 19. Tip: Some objects will recover deformation, but others will not, depending on the material of the selected object and the applied force. 20. Tip: Pull the same spring with different forces and observe the deformation of the spring; Demonstration method: if the deformation of the spring changes, explain the effect of force; If not, explain the effect of force?

Section 5 Newton's first law?

1. or; Uniform linear motion II. Original motion state; Law of inertia 3. The water keeps turning by itself; Keep the original state of motion 4.b5 Inertia; Still; It weighs six. B 7。 B 8。 C 9。 C 10。

1 1 . d 12 . b 13。 Omit 14. Buffer 15. Omit 16. Inertia changed to inertia 17. (1) is large; (2) rear wheel; (3) Omit 18. Move around the earth without falling; Inertia of an object?

The balance between the two forces?

1. Static or uniform linear motion 2. Equal to 3. Static; Uniform linear motion; Still; Uniform linear motion 4.20; V.6.b7. D 8。 B 9。 D 10。 C

1 1.D 12。 A 13。 D 14。 A 15。 Tip: it can't be realized, because the balloon rotates with the earth due to inertia and is stationary relative to the earth. Hint: incorrect, they.

Unit test?

1.D 2。 C 3。 B 4。 D 5。 D 6。 D 7。 D 8。 D 9。 C 10。 A 1 1。 C 12。 C 13。 B 14。 A 15。 b？

16 . m； Kilometers; Gravity; Inertia; Exercise; Still; Big?

18. 172.8; 19. The maximum traffic speed cannot exceed 80 km/h; 30 minutes and 20 seconds. Spacecraft; Earth 2 1. Scale; Height 22. Gravity; Motion state 23. Inertia; friction drag

24. Omit 25. Tip: Is the inertia of an object related to its mass? Use inertial knowledge; Close 27. Tip: Is the pressure on an object related to its shape? Tip: use the same object (such as paper) to shrink into a ball and expand it to see if their falling speed has changed; Or do you use two objects to fall from the same height separately or tied together, and compare the time taken to fall?

29. About100 km/h; 3∶ 12 30.( 1)? v =[SX(]h(n- 1)[]t[SX]]？ ; (2)2m/s； (3)47kg 3 1。 Tip: Can you give an example of using and preventing inertia?

Chapter 13 Force and machinery?

Section 1 elastic spring dynamometer?

1. Elasticity; Elastic deformation II. Steel rule, rubber band; Gypsum, dough 3. Proportion 4. Because the elongation of the spring is proportional to the tension within the elastic limit, the longer the spring elongation, the greater the tension. 5.0~5; 0.2; 1.6 6.D 7。 C 8。 A nine. c 10 . 5 . 5； 0~5; 0.2 1 1.A 12。 C 13。 Omit (the answer meets the requirements) 14. (1) is proportional; (2) 1 1; 10 15.( 1) spring dynamometer (2) within the elastic limit, the elongation of the spring is proportional to the tension (3)B 16. The desktop can be deformed; The bright spot position of light spot 17 changes slightly. Omit 18.

Heavy efforts in the second quarter?

1. Mutual attraction; Gravity 2. Vertical downward; Thick vertical line 3. Direct ratio; 10N/kg； 1kg the gravity of the object is10n; ; Not the same as 4. The center of gravity is very low. The position of the center of gravity; The range of the soles of the feet. D 7。 B 8。 D

9. Omitted10.100n; The gravity of an object is directly proportional to its mass,11.d12.a13.c14.d15.

16. Solution: 20t=20000kg? G=mg？ =20000kg× 10N/kg=200000N？

A: The total weight of cars and goods in Xiao Chen will not exceed 200,000 Newton?

17.a A and c; B, the brake bolt lowers the center of gravity to improve the stability; Improve the stability of the dining table by increasing the supporting surface. ?

18. Omit?

Friction in the third quarter?

1. Slide; Rolling; Sliding; Increase the roughness of the contact surface; Increase; Changing sliding friction into rolling friction; Reduce 2.d3.a4.d5.d6 Inertia; Small; Dragon 7. Turn a few more times; Increase the pressure by 8. (1) Change sliding friction into rolling to reduce friction; (2) increasing pressure and friction; (3) increasing the roughness of the contact surface to increase the friction; (4) increasing the roughness of the contact surface to increase the friction; (5) separating contact surfaces to reduce friction; (6) Changing sliding friction into rolling friction to reduce friction. 9.C 10。 (1) try to be smooth; Horizontal, along the desktop direction (2) under the condition of constant pressure, the rougher the contact surface, the greater the friction force, and the greater the pressure under the condition of the same contact surface; The greater the friction.

1 1. The deep sole pattern actually increases the roughness of the contact surface between the sole and the ground; If there is fine sand on the ground, the sliding friction between the sole of the foot and the ground becomes rolling friction. These two considerations are to increase the friction between the athlete's sole and the ground. 12. Wrong. In this case, the friction force is the force to prevent the iron bar from sliding down, so according to the balance of the two forces, as long as the iron bar is still in hand, the friction force is certain. 13. The chain uses ball bearings to change sliding friction into rolling to reduce friction; Put a patterned sleeve on the handlebar to increase the roughness of the contact surface to increase friction; There are patterns on the tires, increasing the roughness of the contact surface to increase the friction, etc ... 14. Put some rollers under the box to turn sliding friction into rolling friction and reduce the friction between the bottom of the box and the ground 15. (1) A and b; A, C (2) As shown in Figure A, firstly, drag the wood block in a straight line at a faster speed and write down the instructions. Do the same operation at a slower speed, and then compare the indicators twice. If they are equal, it doesn't matter; If they are not equal, this is important. 16. Whether the sliding friction is related to the size of the contact surface; Relevant (or irrelevant, corresponding to the following) (1)C, d, e; (2) 1. Put the cuboid block on the board, pull it at a uniform speed with a spring dynamometer, and count the pulling forces. f 1； 2. put the cuboid block on the board again, as above, and write down the tension? F2 ^ 3。 Compare? F 1 、? The size of F2, if? F 1 equals? F2, the conjecture holds. If they are not equal, the guess is not established; (3) ellipsis; (4)? f？ 2 & gtF 1 17。 (1) The magnitude of fluid resistance is related to the moving speed and stress area of the object; (2) The underwater parts of rockets, airplanes, racing cars, automobiles and ships are streamlined. 18.( 1) Balance of two forces; Equality; (2)0.20,0.60,0.79,? 1.0? , 1. 19, 1.40,2.0; (3) Sliding friction is proportional to pressure; 4N 19。 (1) control variable; (2) equality; Indirect?

The fourth quarter lever?

1. Save labor; Bottle cap screwdriver; Work hard; Tweezers; Equal arm; Balance 2.a3.d4.d5.a6 Sketch 7.b；; An eight. Fulcrum; Save effort; Save effort 9. Answer? ; 10.( 1) spring dynamometer; The scale (2) is omitted 1 1. Lower part; Save effort; Draft 12. Pry upward, because the ratio of force arm to resistance arm is greater when prying upward than when prying downward, so prying upward is more labor-saving. 13. Right; Right14.d15.c16.c17. (1) The folded end is inclined; (2) the arm of force is reduced; (3) After being folded in half, the gravity remains unchanged, and the center of gravity moves to the fulcrum, making the moment arm smaller 18. (1) level; Convenient to measure the arm of force; (2) Hang two hook codes on the right side 3 grids away from the fulcrum; (3) There is no addition and subtraction between different physical quantities, and the experimental data is special, so many measurements have not been done?

Section 5 Other simple machinery?

1. Down; Crown 2. Crown block; Change the direction of tension; Do not work hard; Moving pulley; Get twice the result with half the effort; The feed distance is 3.400; 2; 200; 4 4.60 0 5. Axle; Inclined plane; Lever 6. D 7。 C 8。 C 9。 B 10。 (1) Because the pulley block lifts objects with three ropes, why? G=3F？ = 196N×3=588N (2) Because the pulley block lifts the object with three ropes, why? s=3h？ =6m 1 1。 Draft 12. (1) The crown block is not labor-saving; (2) Pulley block consisting of crown block and moving pulley13.2; 80N 14。 Make it bigger and thinner. 15. Shift gears, take the S-shaped route, accelerate before going uphill, etc. 16. Omitted 17. (1) The slower the slope, the more labor-saving; (2) The stairs should be designed as gently as possible. 18.( 1) Change the direction of the force; (2) crown block; (3) cranes on construction sites?

Unit test?

1.c2.b3.b4.b5.c6.b7.b8.c9.c10.b1.c12.d13.d. Fixed; Change the direction of force 16. Change sliding into rolling; Friction 17. Changing the roughness of the contact surface will increase the friction 18. Less than; Labor saving19.100n; Minus 20. Increase the pressure; Increase the roughness of the contact surface; Beneficial; Brake 2 1. Sketch 22. Sketch 23. A uniform straight line; The balance between the two forces; Cylindrical pencil; Block a; ? f？ 1 > F2 24。 (1) left; (2) Hang three hook codes in two places; Hang two hook codes in three places; (3) Make the experimental conclusion more scientific. 25.( 1) As can be seen from the data in the table, when using the crown block, the gravity on the shell of the spring dynamometer is not considered; When using a moving pulley? f？ 2≠G？ /? 2, because the gravity on the moving pulley is not considered. (2) When using the crown block, use the spring dynamometer upside down (or pull the spring dynamometer horizontally; Or measuring the gravity of the spring dynamometer before the experiment). When using the movable pulley, it is necessary to measure the hook code and the total weight of the movable pulley first, and then compare the relationship between tension and total weight (or use a light pulley or increase the hook code weight).

Examples of physical principles (or principles)

1 pedals, tires and other patterns. Increase the roughness of the contact surface and increase the friction.

Both front and rear wheels of bicycle are equipped with rolling bearings, and sliding friction is replaced by rolling friction.

Add lubricating oil to the bicycle chain to reduce friction.

When driving on a level road, you can drive forward even without stepping on the accelerator. Bicycles have inertia.

27. slightly 28. The power arm is not enlarged. A metal sleeve is sleeved on the wrench handle, which can enlarge the power arm and loosen the bolt. ?

Chapter 14 Pressure and Buoyancy?

Strong in the first quarter?

1. Vertical; Stress; Stress; Stress zone; ? p =[SX(]F[]S[SX]]？ ; Pascal 2.2× 104? ; 2× 104? 3.490; 980 4.40 5. A 6. D 7。 C

8. Increase the stress area and reduce the pressure on the ground; Increase the roughness of the contact surface to increase the friction.

9.4:1(inching: if the minimum pressure is expressed as? p 1=[SX(]？ g？ [] 4× 2 [sx]], and the maximum pressure can be expressed as? p？ 2=[SX(]G？ [] 1×2[SX])

10.

1 1.( 1) Relationship between pressure effect and pressure size (2) Relationship between pressure effect and stress area.

(3) pressure; area of thrust surface

12.( 1) pressure; pressure

(2) Speed limit can avoid the danger caused by inertia, and load limit can protect the road surface.

13.( 1) 1.5× 105? N (2)2.5× 105？ protactinium

14.( 1)? G=mg？ =500N+200N=700N？ F=G？ =700N，？ p =[SX(]F[]S[SX]]？ =7× 10? 4pa？

(2)? p =[SX(]F[]S[SX]]？ =700N/0.0002m2？ =3.5× 106? Pa & lt5× 106? Pa won't puncture?

What is the pressure of liquid in the second quarter?

1."