ch01LecturePPT

1、Lecture PowerPointCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.Basic RequirementvTaking Part in ClassvMidterm exam 30 pointsfinal exam 40homework 20In-class exercises 10 100 pointsvReference BookvHomeworkvWhy does the rainbow appear in the east?vWhat caus

2、es the different colors?vWhy are the colors in the fainter rainbow in reverse order?Spirit of InquiryScientific EnterprisevHow do scientists go about explaining things?vHow do scientific explanations differ from other types of explanations?lRead previous ideaslTest these ideas against observationslI

3、nvent an explanation or hypothesislDevise experiments to test hypothesislReport results of experimentslWithstand the test of criticism and modificationsAn acceptable explanation must agree with what is observed.An acceptable explanation must have predictions that can be tested.An acceptable explanat

4、ion must stand up to criticism.Spirit of InquiryAt times, we all use the scientific method in our everyday activities.Scope of PhysicsvThe study of the basic nature of mattervThe most fundamental sciencelExplains fundamental interactions of chemistry, biology, etc. at the atomic or molecular levelLi

5、fe SciencesBiologyHealth-related disciplinesPhysical SciencesPhysicsChemistryGeologyAstronomy, etc.Scope of PhysicsvThe study of the basic nature of mattervThe most fundamental sciencelExplains fundamental interactions of chemistry, biology, etc. at the atomic or molecular levelvThe most quantitativ

6、e sciencelHeavy use of mathematicslNumerical measurementsvCan be described more simply and cleanly than other sciencesvNOT just a collection of facts to memorize!Historic character in physiccal historyAritotle (Greek):force will set object to move!Mohist(China):principle of leverGalileo Galilei(1564

7、1642 Italian physicist):inertia motionSubfields of PhysicsvClassical PhysicslMechanics - forces and motionSubfields of PhysicsvClassical PhysicslMechanics - forces and motionlThermodynamics - temperature, heat, energyFig. 1.5Subfields of PhysicsvClassical PhysicslMechanics - forces and motionlThermo

8、dynamics - temperature, heat, energylElectricity and MagnetismlOptics - lightFig. 1.4Subfields of PhysicsvClassical PhysicslMechanics - forces and motionlThermodynamics - temperature, heat, energylElectricity and MagnetismlOptics - lightvModern PhysicslAtomic physics - atomslNuclear physics - nucleu

9、s of the atomlParticle physics - subatomic particles: quarks, etc回旋加速器在歐洲加速中心，加速器分布在法國和瑞士兩國回旋加速器在歐洲加速中心，加速器分布在法國和瑞士兩國的邊界。加速器在瑞士，儲能環(huán)在法國，產(chǎn)生的高能粒子能的邊界。加速器在瑞士，儲能環(huán)在法國，產(chǎn)生的高能粒子能量為量為280億電子伏特。億電子伏特。在美國費(fèi)米加速實(shí)驗(yàn)室回旋加速器，環(huán)形管道的半在美國費(fèi)米加速實(shí)驗(yàn)室回旋加速器，環(huán)形管道的半徑為徑為2公里。產(chǎn)生的高能粒子能量為公里。產(chǎn)生的高能粒子能量為5000億電子伏億電子伏特。特。Subfields of Physicsv

10、Classical PhysicslMechanics - forces and motionlThermodynamics - temperature, heat, energylElectricity and MagnetismlOptics - lightvModern PhysicslAtomic physics - atomslNuclear physics - nucleus of the atomlParticle physics - subatomic particles: quarks, etclCondensed matter physics - solids and li

11、quidsSubfields of PhysicsvInterdisciplinary FieldslBiophysicslGeophysicslAstrophysicsPhysicists: fundamental understandingEngineers: practical applicationsOften overlapping roles從樹中獲得電力從樹中獲得電力 Get electric powerFrom tree orhair!Let blind people see !Measurement and MathematicsvCareful measurements a

12、re needed to test explanationslDifferent theories predict different resultslMeasurement reveals which theory is correctlFor example, motion of a cannonballMeasurement and MathematicsvThe language of mathematics is convenientlFundamental relationships can be stated preciselylEquations can be manipula

13、ted to form different relationshipslFor example, altering a pancake recipeSummary 3Physical quantityPhysical quantityvSay a plank is 2 metres long.This measurement is called a physical quantity.It is made up of two part 2 m magnitude unitBase UnitsScientific measurement are made using SI unit (SI: S

14、ystem International dUnits ） kg:kilogramLength(L)m: meter,inch,mileTime(t)s:secondMass(m)CentigradeFehrenheitTemperature 1m :is light travel the distance in vacumm for 1/299792458 s. 1s :SI derived unitsSI derived unitsvThere is no SI base unit for speed. However, speed is defined by an equation.If

15、an object travel 12m in 3s:vThe unit m/s is an example of a derived SI unit.It comes from a defined equation.some derived units have special names.For example, 1joule per second(1j/s) is called 1 watt(w)smsmtimelengthspeed/4312PrefixesPrefixesvPrefixes can be added to SI base and derived units to ma

16、ke larger or smaller unitprefixsymbol valueprefixsymbolvalue pico p10-12 kilo k 103 nano n10-9 mega M 106 micro 10-6 giga G 109 milli m10-3 tera T 1012Scalar and vectorScalar :mass, length, temperature. vector : speed, acceleration, momentum. Vectors : it can be represented by arrow OP, with the len

17、gth and direction of the arrow repersentting the magnitude and direction of the vectorOPoPA Vectors are quantities which have both magnitude(size) and direction.Adding vector: CABCartesian coordinate system: kAjAiAAzyx is along OX,OY,OZ directionkji和,OXYZBACTwo dimension condition:jAiAAyxOXYxAyAxyAAtgjBAiBAABjCiCCyyxxyx)(