What are the seven answers in the new science class? Wuhan edition! ! !

1. 1 What is sports?

Lesson 65438

I.1.d2.c3.a4.d2.1.× 2.× 3. √

3. 1. Linear motion curve motion of spatial positioning machinery II. Transformation movement, life movement

3. Mechanical machinery life thermoluminescence (or chemical movement) machinery

second kind

I. 1.b2.b 2, 1.×2.×3 .*

Three, 1. Floating white clouds (mechanical movement) Birds fly over (mechanical movement) Children chase (mechanical movement) Windy (mechanical movement) Drifting (mechanical movement) 2. Robot life 3. Density air buoyancy thermal motion mechanical motion

(1) mechanical movement (2) In the same time, for example, a month or even longer, the length of nail growth and the distance of land movement are accurately measured respectively, and then compared.

1.2 moving or stationary

Lesson 65438

I. 1. C2.D3.D4.C5.D2， 1.× 2。 √ 3.× 4.× 5.√.

Three, 1. Motion, static motion, static motion II. Static motion 3. Static motion 4. Bus no.5. Ground carriage 6. Static motion, static.

4. 1. That's right, because the reference object can be chosen at will. (Example omitted)

This is an open question, as long as it is meaningful.

second kind

I. 1.d2.a3.b4.d5.c

2. 1. Ground motion 2. Clouds and the sun 3. The driver tumbled 4. The moon's rotation period is the same as its rotation period around the earth.

Three, 1. Three students have reason, because they chose different reference objects. A take the ground as a reference; Second, take another faster train in the same direction. And student c takes himself as a reference.

2. As long as you can answer relatively static conditions and applications.

1.3 fast or slow

Lesson 65438

I.1.d2.b3.c4.c5.c6.c7.c8.a.

1. Analysis: When measuring the length of an object with a scale with a minimum scale of 1 mm, it must be accurate to mm, and one digit below mm must be estimated. So to judge whether the data is correct, we can see whether the penultimate bit of this data is the smallest mm bit. If it is, it is correct; If not, it is wrong. ∵ 1.8 dm The second last place is dm. 18.2cm inversion

The second digit of the number is cm. 182.34 mm The penultimate position is below mm, and the above data are incorrect. Only the penultimate position 182. 3 mm is mm, so option C is correct. Answer: c

Two. 1 .× 2 .× 3 .× 4.√ 5 .×

Three. 1.4.20 2mm 2. (1) decimeter (2) millimeter (3) centimeter (4) cubic meter. The average value after repeated measurement is 3.72 4. 15.8 5. 105.

4. 1. Analysis: A piece of paper is so thin that it is impossible to directly measure its thickness in millimeters. Therefore, a special measurement method must be adopted, that is, the "accumulation method" is used to stack the same paper to make it have enough thickness, which can be measured by the scale of millimeters, and then the thickness of a paper can be indirectly measured by dividing the total thickness by the number of sheets.

Experimental steps:

(1) You can take science textbooks P 1 to P 178, stack them up and press them hard; (2) measure the total thickness with a millimeter scale;

(3) Divide the measured total thickness by the number of sheets of paper 89 to obtain the thickness of a sheet of paper.

2 . h = h 1+H2+H3+H4 4 = 13.8 1cm+ 13.82cm+ 13.80cm+ 13.83cm 4 = 13.8 15cm h = 13.82cm .

2 class hours

I. 1.a2.a3.c4.d

Second, 1. The speed of the distance traveled per unit time is V S T V = S/T 2. ( 1)= 3.6km/h(2) 1.25 1.5× 10-3 14.4 3。

Third, 1. The uniform crawling speed of B boy A is 0.5m/s2.2.5h.

The third category

I./kloc-0 1.C2.B3.A4.D

Second, 1. The average speed of uniform linear motion at any time or any position. 2.( 1) Scale of stopwatch (2) BCBC BCBC BCBC minus 3. 1: 6.

Seven answers to the new science class

4. Driving time V = ST 5.20 18 27.2

Three. 1.0.5m/s1.25m /S4 m /S2. ( 1) 18min 8min 13.5h(2)95:4km/h。

Category 4

I. 1.b2.c3.c4.d

Second, 1.vt s/v unified 2.3×105km/s3.6.9×105km4.766.7s.

Three. 1. 1080 m2 . t = SV = 12km 40k m/h = 0.3h = 18min。

A volume of scientific quality evaluation questions

One,

Topic 1 2 3 4 5 6 7 8

Answer A B B B A B B C

Two. 1.× 2.√ 3.√ 4.× 5.×

3. 1. 1 mm 1 cm2 100 636 3. Reference 4 for position change. Trees on the roadside or trains or passengers on the ground 5.1mm6.644 4.8 7.20188.dm0: 22h9. Time travel distance travel time 65433. S meters kilometers per second/hour 1 1. +0. Static motion 12. Km mm m/s

Four. 1 . v = s/t = 1200m/ 1min = 1200m/60s = 20m/s。

2.5400 3000 3. Train crossing time: t = ST = 980+200m10m/s =118s.

1.In the relay race, students who receive the baton should accelerate in the same direction. When two students are at the same speed, that is, relatively still, the baton will not go wrong. 2.( 1)3 m/s (2)3 minutes 3.33 m/s 0. 78 m/s 2 m/s

Scientific quality assessment volume b

One,

Theme 1 2 3 4 5 6 7 8 9

Answer A D B B D C B B B b B B

Ii. 1.200 720 2. Still 3. A car. 8cm/s10cm/s8.8cm/s5.480.

1000 16.67 6. Train 300 7. C analysis: A, B and C each take themselves as reference objects, that is, they assume that they are stationary objects in advance to observe the movements of the other two cars. A sees that B's car is stationary, but it comes to the conclusion that B moves as fast as A. When B sees that C's car is far away from him and C sees A's car backing up, it can be concluded that C's car is in front of A's car, so it moves fastest. Of course, the above two judgments are based on the ground as a reference, and the results are obtained. 8. 17.49 9.2.5 10. "Still" or "driving to the left" or "still" or "driving to the left" has different reference objects 1 1. B move the same distance. The comparative exercise time is 12. Km/s > m/s > km/h > m/min 13.20 20 14. (VL x v2)/22v 1 v2/(v 1+v2)。

Three. 1.(1) v = 36 km/h t' = 0.45 h = 27 min (2) When driving at the lowest speed limit v2=60 km/h,

T2 = s/v2 = 3h. When the maximum speed limit of V2 is' = 120km, T2' = s/v2' = 1.5h is 1.5=3 h.

2 . t = s v = 6m 2m/s = 2s 30m 3 . 0 . 1h 1800m

4.1.6S4.17m/s50s3m/s is greater than 2. V = T (1) smaller (2) larger.

3. Because, although A retreated 10 m from the starting line, A ran very fast after the start. At the same time, A runs 50 meters, B runs 40 meters, and finally everyone has to run 10 meters, which is the 10 meter sprint. A runs fast, but in the end, A must reach the finish line first.

4. Let the motorboat speed be V, and the current speed be V (and V >；; V), the distance is S. Time to go back and forth in still water t= 2s v ① In flowing water, time to downstream t 1= s v+v, time to upstream t2 = sv-v.

Total round-trip time t1+t2 = SV+V+SV-V.

= 2sv v2—v2

= 2s v( 1—t=v2 /v2)

=2s v. 1 1—(v2/v2) ②

Comparing ① and ②, we can know that (t 1 T2) > t means that the time in still water is shorter than that in running water.

2 force

2. 1 the role of force

Lesson 65438

I.1.b2.c3.a. 1.× 2.√ 3.×

Three. 1. Motion state of mutual shapes of objects 2. Gravitational earth 3. Four feet. neglect

second kind

Three New Science Classroom Seven Answers

I.1.d2.b3.b4.b2.1.× 2.× 3. *

Three. 1. Niu Li pulls the grounding spring dynamometer 4 again. Within the elastic range of the spring, the length of the spring extension is proportional to the tension. Fourth, prevent the hook of the spring dynamometer from getting stuck in the housing.

Verb (abbreviation of verb) (50g/l0g) × 2cm =10cm25cm-10cm =15cm.

The third category

1. 1.d2.c 2。 1.x2.x3.x。

Three. 1. Point of action in dimension direction 2. Direction and action point. 1. Omit 2. Omit 3. Omit.

2.2 under the action of gravity

I./kloc-0 1.a2.a3.b4.c5.a

Two. 1.× 2 .× 3.√ 4 .× 5.√ 6.√

Third, 1. The attraction of the earth is cattle. The earth is vertically downward. 2. The gravity of an object is directly proportional to its mass kg n..

9.8 N/kg 9。 8 Newton The gravity of an object weighing kg 1 kg is 9.8 N3. The direction of vertical and horizontal gravity is always vertical downward. The gravity earth is vertically downward. 5.588 N70 Kg6。 486 N7。 The motion state of gravity vertically throwing down the center of gravity.

5.( 1) The gravity on an object is directly proportional to its mass.

(2)① Wuhan and Shanghai; ② Equator and North Pole; ③ Different latitudes.

Six, spring dynamometer, thermometer put forward to guess the iron temperature is constant, the position is unchanged, the iron is hung on the spring scale and weighed by gravity, and the iron is heated on the alcohol lamp, and then the results of two gravity comparisons are weighed.

2.3 Is there a similarity between motion and stillness?

I.1.b2.d3.d4.c5.d6.d7.c8.c9.d10.b.

Two. 1.× 2 .× 3.√ 4 .× 5 .× 6 .×

3. 1. Static uniform linear motion equilibrium state equilibrium force A pair of equilibrium forces 2. Equal but opposite 3. 15N4. 196 N pull 196 N vertical upward rope 5.3x105n is equal to or equal to 6.0N7. The change force of the vertical downward center earth speed with the weight of 39.2N is the reason for changing the motion state of the object 2.

Fourth, 1.

Verb (abbreviation of verb) solution: m = PV = 7.9×103kg/m3× 0.5m3 = 3.95×103kg.

g = mg = 3.95kg×9.8N/kg = 3.97 1× 104N

∵3.97 1× 104N & lt； 4 × 104N ∴ can be lifted.

6.( 1) The number of paper clips hanging under the umbrella (or the area of plastic film) (2) The number increases and the falling time decreases; When the quantity decreases, the falling time increases (when the area of plastic film increases, the falling time increases; The area of plastic film is reduced, and the falling time is reduced) (3) Different experimental schemes can be designed. (Measuring time or comparing with each other) As long as the selected equipment is consistent with the designed experimental scheme, ① Different numbers of paper clips (or parachutes with different film areas) and stopwatches (or other timing tools) ② Scheme 1: Directly measure the parachute falling time. The experimental steps are as follows: a) release any parachute from the balcony and measure its falling time t1; B) Repeat the experiment by changing parachutes (different number of paper clips or different film pasting area), measure the falling time t2, and compare the size of t 1 and t2.

Scheme 2: Two different parachutes (with different numbers of paper clips or different membrane areas) fall from the same height at the same time, and the landing sequence is compared, and the experimental steps are omitted.

2.4 Friction and us

I . 1 . C2 . C3 . D4 . C5 . B6 .( 1)D(2)A，B (3)C 7。 b，c。

8.C 9。 A 10。 B

Two. 1.× 2.√ 3 .× 4 .× 5 .× 6.√

3. 1. Rolling and sliding static 2. Increase the pressure and increase the friction 3. 100 N Slow down horizontally and move in a straight line to the left 100 N Keep the original speed and move in a straight line at a constant speed 4. Smooth contact 5.234.

6. Uniform straight line 3. 5 The balancing force moves along a uniform straight line 7. Equal to or greater than 8. Reducing the pressure makes the contact surface smooth, rolling instead of sliding increases the pressure and increases the roughness of the contact surface. Fourth, ellipsis

When sprinters start, they should push back with the greatest strength, so as to get a relatively high speed in the shortest time. If you wear ordinary sports shoes, the back pedal force is greater than the maximum static friction between the sole and the runway, and the athlete's feet will slip and move backwards, which will affect the competition results.

6.( 1) When the roughness of the contact surface is the same, the greater the pressure, the greater the friction.

(2) 2 and 3, when the pressure is the same, the rougher the contact surface, the greater the friction. (3) Control variable method.

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Four new science classroom seven answers

2.5 can't move or stop.

Lesson 65438

1. 1.b2.d3.c4.b5.b2， 1.x2.√ 3.× 4.× 5。 √ 3, 1. Move on. 2. Being at rest and doing linear motion without external force. 3. Roll back and roll forward during the break.

(2) The less resistance the car receives, the longer the car moves.

(3) If the car moves on an absolutely smooth horizontal plane, that is, it is not affected by resistance, then the car will always move in a straight line.

2.( 1) Stones thrown by people always deviate from the throwing direction and fall back to the ground.

(2) When the speed of throwing the object is large enough, the object will leave the earth and make a circular motion around the earth.

(3) artificial earth satellite

second kind

I.1.c2.c3.d4.a5.c6.a.ii. 1.× 2.× 3.√4.×5.√

3. 1. The vertical inertia is affected by gravity 2. Any stationary uniform linear motion. a，B，D 4。 A static state or a state of uniform linear motion is an inherent static motion 5. After that, the inertia of the stationary object is 6. Inertia

4. 1.( 1) Fly out without moving (2) A. Overcome inertia, B. No inertia, C. Suffer inertia. (3) Force, change and inertia. 2.( 1) Speed and ground conditions. (2) Don't drive too fast in rainy and snowy weather, but slow down.

3. (omitted) 4. (omitted)

Scientific quality assessment volume a

One,

Topic 1 2 3 4 5 6 7 8 9 10

Answer D D D B A C D C D C D C D C D C D C D C

Topic11213141516171819 20.

Answer D A C D C D D D C A

Two. 1.√ 2.× 3.√ 4.× 5.× 6.× 7.√ 8.× 9.× 10.√

3. 1. Interform 2. Weight 4. 9 Earth 3. Effect of action point in size direction 4. Pressure friction 5. Inertia 6. Equal in magnitude and opposite in direction act on the same straight line 7. A reasonable answer can be omitted from 4.

Verb (abbreviation of verb) 1.( 1) Speed (2) Resistance (friction) never stops moving (doing uniform linear motion) Newton first (3) Same car, same slope, same height, different surfaces 2.

Scientific quality assessment volume b

One,

Topic 1 2 3 4 5 6 7 8 9 10

Answer D B A A B C D A B D b d

Topic11213141516171819 20.

Answer d b d d d d d d b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b

Two. 1.√ 2.× 3.× 4.× 5.√ 6.× 7.× 8.√ 9.× 10.×

Three. 1. action point size direction action point 2. 10 10 10 becomes smaller by 3. Gravity motion state 4. Whether perpendicular to the direction of gravity or vertical downward 5. Reduce and increase 6.5N

7.6× 104 six×104 four. neglect

5. 1.( 1) 9.8 is directly proportional to 29. 4N (2) The horizontal low gravity direction is vertical downward (3) the center of gravity.

2.( 1) Because the pulling force of the spring dynamometer on the wood block and the friction force of the wood block are a pair of balanced forces.

(2) B (3) Place the cuboid block on the horizontal long wooden board, and use the spring dynamometer to pull the block to slide along a straight line at a uniform speed, and compare the readings of the spring dynamometer in step 4 and step 1. (4) Omission

3 Cloudy to sunny, cold and warm

3. 1 weather change

Lesson 65438

I.1.c2.b3.a.ii. 1.√ 2 .× 3.√ 4.√ 5 .×

3. 1. Short-term movement changes 2. Cloud 3. Heat, frost, drought and flood, storm and hail. Thunderstorms don't cross the river.

Four. 1.( 1) southeast wind, cold wave and heavy snow (2) military life traffic (2) (1) c (2) a.

second kind

I. 1.b2.d3.c4.c5.d6.d

Two. 1 .× 2 .× 3 .× 4 .× 5 .× 6 .×

Third, 1. ℃; 7 1 2. High altitude ground observation. The wind force is 0 ~ 1 2 4. Temperature, humidity, precipitation evaporation, wind and clouds. ① Observe the temperature in the louver four times a day at 2, 8, 14 and 20: 00 Beijing time. Observe the wind direction with anemometer and measure the wind speed with wind cup.