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Test type and solution method that the physics makes a diagram and portrait in the stocktaking
Jiangsu province connects cloud harbor City new sea experiment high school always pure(You plait:222004)
According to test physics to try an analysis in 13 cities in 2004 Jiangsu province can know, "make a diagram" reaches to 7~12% with the comparison that"portrait" have, and presents year by year increased trend.At close to in test of review, teacher's value in making a diagram degree has to descend, and the student's solution to the portrait strategy control not system, not well-trained, cause through the years in pass examination these rate in cent of lose of two types ofseses high.The writer aims at the above-mentioned existent problem in test the front review, designed 2 to review special subject and share with reader them now.
Special subject a:medium test to make a diagram to categorize shallow Xi
The writer tests physics to try from at the rightness province 13, Jiangsu 2004 with connect cloud harbor City for the last few years in test physics to try a maneuver of analysis, contrast in detection, in test physics to make a diagram to involve mechanics, the heat learn and optics and electromagnetism learn four greatest realms, can divide 15 kinds of types.
The mechanics makes a diagram
The diagram of dint show and sketch map
Mainly investigate:the diagram of gravity or buoyancy show;Two dint steady hour objects are subjected to dint sketch map.
For example:29(Nanking City), 31(2)(have no tin City), 20(Suzhou City), 28(1)(river City in the town), 11(south City), 17(the Tai state City), 28(salt city), 28(connect cloud harbor City, 2000)
Review important point:the â‘  want to clear up to actually draw which object the dint be subjected to;The â‘¡ wants to clear up painting object which the diagram of dint show or sketch map;The â‘¢ shows according to the diagram of dint or the diagram important point, science of the make of sketch map, make of norm diagram.
The sketch map of lever balance
Mainly investigate:lever balance hour of the technique of painting of dint and dint arm
For example:31(Nanking City), 24(Xu state City), 23(Huai Anne City), 23(the night move city), 39 and 40(connect cloud harbor City, 1999)
Make diagram important point:the â‘  seek quasi- fulcrum;The â‘¡ truth or falsity line wants to draw definitely;The â‘¢ makes the diagram mark in the diagram to want accurate, to in response to.
The imitate of pulley set assembles diagram
Mainly investigate:"must a move" with the construction of "two settle two move" type pulley set
For example:24(2)(Yang state), 26(connect cloud harbor City, 2003), 26(connect cloud harbor City, 2004)
Make diagram important point:the â‘  want to keep firmly in mind model diagram;(in common use pulley set the model only has 7 kinds)The â‘¡ wants to review a pure an idea;The â‘¢ wants a check.
Physical principle sketch map
Mainly investigate:the liquid inner part press a strong characteristics, heavy perpendicular line application, connect a machine work a characteristics
For example:28(4)(river City in the town)
Make diagram important point:make a pure principle contents, contact a life application.
Hot learn to make a diagram
Temperature when crystal melt(solidify) to heat(seethe) with liquid the portrait for change make diagram at any time
For example:26(south City)
6.Temperature when specific heat permitted different material heating the portrait for change make diagram at any time
For example:27(Tienjin City)
7.The thermometer reads a number with mark number make diagram
For example:29(1)(river City in the town)
Elucidation:this type of make diagram to investigate less in recent years, investigate to appear in the portrait more, so can slightly speak.
The optics makes a diagram
Light of the glint light road diagram peace noodles mirror become to be like to make diagram
For example:21(Suzhou City), 12(b)(south City), 18(the Tai state City), 26(Xu state City), 29(salt city), 27(b diagram)(connect cloud harbor City, 2001), 25(connect cloud harbor City, 2003)
The light road diagram and convex lens of the refract of light become to be like to make diagram
For example:30(Nanking City), 28(2)(river City in the town), 12(a)(south City), 22(the Yang state City), 27(c)(connect cloud harbor City, 2001), 41(connect cloud harbor City, 1999), 27(connect cloud harbor City, 2000)
Elucidation:this two types ofs investigate of the knowledge noodles be more whole, in review should completely review of system, can't neglect 1.
10.The optics"black box son" makes diagram
For example:29(often state City), 14(1)(sea Dian area in Peking)
Elucidation:this mainly investigates an optical component at the glint of light or refract of application, therefore can also chase it and two types of ex-s
Type merger, just make a diagram difficulty slightly a little bit high.
The electromagnetism learns to make a diagram
11.Design the simple electric circuit makes diagram
For example:14(south City), 27(Xu state City), 24(the night move city)
Elucidation:this kind of is a type of new which combine to become to win to pass examination at present with"solution", like 13(Sichuan province).
12.The conjunction of real object electric circuit makes diagram(include electromagnetism to make diagram after the conjunction of electric appliances control electric circuit)
For example:34(3)(south City), 30(1)(Xu state City), 26(1)(Huai Anne City), 31(1)(the night move city) are 27(a)(connect cloud harbor City, 2003)
Elucidation:this kind of usually combines with experiment and have of call it as "the experiment make a diagram" in the subject of examination.
The family simple electric circuit imitates to install diagram
For example:13(south City), 19(the Tai state City), 24(Huai Anne City), 31(salt city)
Elucidation:this kind of mainly investigates "three eye electric outlets and fuse" with"Luo lamp bulb and control switch" and the front line, the conjunction of zero lines and ground lines.
The electromagnetism contact problem makes diagram
For example:32(south City), 31(1)(have no tin City), 30(often state City), 28(3)(river City in the town), 23< BRs>
(The Yang state City), 20(the Tai state City), 25(Xu state City), 30(salt city);27(a diagram)(connect cloud harbor City, 2001)
Elucidation:this kind of passes examination to present to pass to increase a situation in in recent years of, mainly investigate "switch on electricity a spiral line tube the magnetic field of the surroundings" and"the right hand be spiral to settle then"'s two knowledge to order and also appeared an experiment design.
The electromagnetism learns "black box son" to make diagram
Elucidation:this kind of similar to"the simple electric circuit design make diagram", the examinee reviews two electric resistances in "black box son" in response to the point or
The "dotted line frame" medium string merges a conjunction problem.
The student reviews through a special subject, take into again to enhance to practice and avoided training without the target with"naval battle", economical many times for review, raised to review effect.
Special subject two:medium test a portrait example Xi
The physical portrait is an image to describe physical appearance, one of the tool of process and regulation is also mathematics knowledge an applied"grasp a hand" is in the physics.Therefore, the teacher guides a student to control a portrait solution a method, not only can make the student reply medium test of challenge, can also train the quick in action and innovation of student's thinking.
The familiar portrait of portrait
Is shown as diagram, total 11 kinds.
(10)
(11)
The writer think that see first while solve above-mentioned portrait pure 2 sit mark stalk to mean respectively what physics quantity, initial understanding sits mark in the meaning of portrait;Secondly hold tight diagram in of a little bit special, line, even noodles to comprehend the deep meaning of portrait;End, comprehensive analysis information solution within portrait.Such as the diagram(1), mean the relation between road and time, is sat a mark by arbitrarily a point Zongs in diagram with horizontal sit an object specific value's homology can get an object to make to evenly and soon and straightly exercise;Diagram(2) means the relation between speed and time, obviously see an object being to can not hold still;Diagram(3) means the relation between object quality and of physical volume, it inclined rate mean that kind of density of object, tilt to one side degree more big, mean that its density is more big.Can also see from the diagram, the density of of same race material isn't with the quality of the object or the change but change of the physical volume, so the density is a kind of attribute of material;Arbitrarily a point Zongs in diagram(4) sit a mark with horizontal sit to mark clearly of the specific value be the reciprocal(1/R) of conductor electric resistance, so, tilt to one side the degree more and greatly means the electric resistance of that conductor the value is more small;The diagram(5) means that the liquid inner part press strong and the relation of of liquid depth, as long as compute a Zong to sit a mark with horizontal sit an object specific value, can make us associate P=the formula of ρ gh;Diagram(9) is mean a kind of new have fever material-PTC of the electric resistance is with the regulation of temperature variety.From medium we can see: be temperature low in a certain set of temperature value(call "reside in order temperature" in the physics), its electric resistance lets up with the go up of temperature.According to the P=the U2/R can know, the have fever of conductor power is enlarge, and the conductor is placed in to heat appearance;When the temperature attains the temperature value of enactment, along with the go up of temperature, the electric resistance of conductor become big, the have fever of conductor power let up, and this stage people are called "heat preservation stage";Diagram(10) with(11) mean of all of physical processes be not unique, should concretely the circumstance be concretely analytical.
The example analyze
In 2004 in test 13 City physicses in Jiangsu province to try in, there is following portrait being provided for reader to check:34(2)(Nanking
City), 17 with 38(have no tin City), 26 and 33(south City), 21(the Yang state City), 31(3)(Xu state City), 29(Huai Anne City), 5(connect cloud harbor City), 11.(night move city)Moreover, 23(proper Chang City, Hubei), 20(the county in Huang in Qing Lake), 19 with 33(Dalian City), 12(Fuzhou City) is also portraits.So, how solve a portrait underneath of two example is only provided for reader to make reference to.
Example 1:such as figure 1 show, 1 with 2 is two kinds of solid center metal of quality and physical volume relate to diagram line.Constitute two kinds of different metal alloys: two kinds of metals etc. physical volumes and etc. quality mixture now, ask you try to draw in sit the mark stalk one these two kinds of metal alloys of quality and physical volume relate to diagram line 3 with 4 rough positions.(Establish two kinds of hybrid processes in, metal alloy of total accumulate to always equal two kinds of metals physical volumeses to match.)
Resolution:such as figure 2 show, be 1,2 two kinds of metals of quality is m 0:00, their physical volumes is V1s and V2 respectively, and the V be 1> V2s.According to the ρ =can get, metals one density ρ 1 small at the metals 2 density ρs 2, namely ρ 1 ρ 3> ρs 1.So, portrait 3 should Be located on inside Ⅱ scope;Again according to mathematics knowledge ρ 4 change to may be done:the ρ be 4==.So, ρ one ρ 4, so, portrait 4 should also within the scope of Ⅱ , but Be located on portrait 3 of make diagram such as the figure above 3 show.

Diagram one figure 2 the figures be 3< BRs>
Example 2:the noodles of certain place desire at lake build a big bridge and descend diagram AN is the sketch map which uses hoist to throw in a cylinder form a stone to anticipate toward the lake bottom.In wholely throw in the process, the stone anticipates to settle speed v by Heng=the 0.1 ms/s descend.Diagram B is the portrait that the steel wire rope pulls dint F at any time t variety.(throw in a stone to anticipate from the beginning just right contact lake before the bottom)T=under 0 time hoist beginnings put a stone to anticipate, neglect aqueous friction resistance, the g takes a 10 Ns/kg.Beg:(1)the lake bottom be subjected to of press of water be strong;(2)cylinder form the stone anticipate of density.
Resolution:can see from the diagram:AB segment mean that the hoist mourns a stone to anticipate evenly and soon to descend(have not come in contact with a surface) toward the surface, at this time F=the G stone anticipate=1400 Ns;Completely immersing while arriving C to order from the B start to order a cylinder form a stone to anticipate to start dip into water didn't be underwater, pull dint F to come to an a minimum value(T=900 Ns), the cylinder form stone anticipates to be subjected to dint at this time such as figure 1 show, is can get by the diagram:the F float=G-T=1400 Ns Ns-900ses=500 Ns.
Can get according to Archimedes' principle:the F float=ρ water gV row, V row=the V stone anticipate.
So, the V stone anticipate=5 ×s 10-2 ms 3.According to the ρ =can get:ρ ===2.8 ×s 103 kgs/m 3.
The classroom practice
(1)Use one hot source of stability to a heating with even object, establish the calories of object absorption
With heat time become direct proportion, get its temperature at any time the portrait for change to is shown as diagram, so this kind of material at the solid and the liquid the ratio of specific heat is(answer:C)
(A) 1:2 (B) 2:1 (C) 1:4 (D) 4:1
(2)In the experiment measurese liquid density, the physical volume(V) of liquid with liquid with permit
The total quality(the m be total) of machine can distinguish dosage tube and weighing scales to measure.The some classmate passes a physical volume of change the liquid, and corresponded to measure the total quality of liquid and container but drew the following m total-the V be four portraits, among them ability exactitude reflection liquid and the container total quality and liquid physical volume of relate to of portrait BE(answer:B)
M ·s-1< BRs>
m3