轉動慣量實驗報告

Measurethemomentofinertiaofanobjectwiththreewirependulum

EnglishName:max

ChineseName:wanghaotian

StudentNumber:1417454061

Major:Electricalengineeringanditsautomation(Sinoforeigncooperativeeducation)

1.INTRODUCTION

1)Aimsoftheexperiment:

1.Toresearchtherotaryinertia,massandform(uniformdestiny)ofoneobject,andtherelationbetweenRotorpositionandtheobject.

2.studythemethodofmeasuringrotaryinertiainthreewiretwistmethod.

2)Briefcontentsofexperiment:

1.Whenthethreewiretwistafterleveling,twistontheplate(α<5degree),Torsionalpendulummovementinthethreewirependulum,bythetheoryoftherotationalinertiaofthedrivendiscfor I0

themoofthetype,Forthequalityofthehangingplate,gistheaccelerationofgravity,Randrrespectivelyareonthefootwallandthethreeplateofthreewirependulumsuspensionpoint'scenterofgravitytothehangingpointdistance.Histheverticaldistancebetweenthetwodiscs.T0isthehangingplatetwistcycle.

2.Ifthequalityofmobjectssymmetricallyonthediscm0undertest，

soI0

TofthetypeistheirSwingcycle.supposek=gRr/4pai2H,soI0=km0T02,I=k(mo+m)T2Iobject=I-I0=k[m0(T2-T02)+mT2]

2.EXPERIMENTAL

1)Apparatus:

Threewiretwist,thecylindersample(two),ringsampleB,level,Astopwatch(0.01s),metricscale(1mm),verniercaliper(0.02mm).

2)Procedure:

1.recordthemassm0ofdisc,andthemassofA,B,mA,mB.

2.1)measuretheinsideandexternaldiameterofdiscD0insideandD0externalbyverniercaliper.

2)measurethediameterofcylindrical DAbyverniercaliper.

3)measuretheinsideandexternaldiameterofannulusDBinsideandDBexternaLbyverniercaliper.

4)measureandcalculatethedistancebetweentheup-circle,down-circleandcenterofacircle,randR.

3.adjustthecolumnstraight,Withlevellevelingfootwall,firstmakelevelparallelwithtwoadjustingscrewconnection,thenwithbothhandsatthesametimeoperatingthetwosuspensionlinelengthadjustingwiththeadjustscrew,adjustthelevelafterheturned90degrees,andlevelanotheradjustingscrew,doittwotimesandyoucanlevelit,measureHbymeterruler.

4.Twistondisc(α<5degree),dotorsionalpendulummotionbysuspensionlineunderthetorsionofthedisc,

5.afterwaitingfordiskdostabilityunderswing,Pressthestopwatchandstartingfrom0foroscillationfrequency,getthetotaltimetowritedownthefullswing50times,andcalculateitscycle.dotheexperiment3times,calculatetheT0

6.putexampleAonthelowercircle,alignitscenterandthedisc'scenter,repeatstep4and5,thencalculatetheT1

7.puttwosameexampleA,insymmetrypositionofcircle'scenter,andmakeitsedgetangentcircle'scenter,repeatstep4and5,thencalculatetheT1

8.putexampleBonthelowercircle,alignitscenterandthedisc'scenter,repeatstep4and5,thencalculatetheT1

3.RESULTS

Datumfrommeasurements:

Table1

t/s

T(30times)

uc,T

1

2

3

4

5

lowerdisc

20.96

19.84

20.06

20.17

20.29

20.269

1.39

0.0047

lowerdiscandring

20.09

19.76

20.19

19.70

19.97

19.942

1.37

0.0047

Table2

lowerdiscm

ringM

mass/g

m=1129

M=403

diameter/cm

D=

19.0

Doutside

14.9

Dinside

10.0

distancebetweentwopointsofupperdisc

a1

7.7

r=

eq\f(a1+a2+a3,3

eq\r(,3)

)

=4.43

a2

7.7

a3

7.65

distancebetweentwopointsoflowerdisc

b1

16.1

R=

eq\f(b1+b2+b3,3

eq\r(,3)

)

=9.33

b2

16.2

b3

16.2

H/cm

43.1

Table3

Lowercircle（m）

Lowercircle（m）+ring

ring

experimentalvalue

I(kg*m2）

0.0051

0.0068

0.0012

Uc1(kg*m2)

1.13x10-5

1.30x10-5

1.21x10-5

I=I+-Uc，1

I(kg*m2）

0.00479

0.00679

0.00119

theoreticalvalue

I(kg*m2）

0.0050

0.0070

0.0027

error(percentage)

4%

2.8%

2.9%

inertiaofthediscandsamplesofAandBoftheexperimentalvalueandandtheoreticalvalue,Calculatethepercentageerror

Momentofinertiaofthecircletothetheoreticalvalueis

MomentofinertiaofAnnulusforthetheoreticalvalueis

4.DISCUSSIONANDCONCLUSION

1.Whenweuseverniercaliper,weneedtoreadthevaluecorrectly.Aftermeasur