.Khi truc quay di qua trung di6rn cua thanh va thanh dang quay cleu vo'i toc do goc 0l tlii dat rlhg mQt vAt nho l€n mdt di€m tr€n thanh rdi dinh chit vaolhantr.. giet momen quan tfnh c[r]
(1)DE CHINH THLTC
* pnAx rn4c wcnfinr-[nicn outx ( z.o aiiimt
Ciu Cho ddng di€n xoay chidu va dong di€n kh6ng OOi tan luot cha)'qua mot cuon dAv thi ^ ^
cdng sudt ti€u thu cua doan mach nhu Ti sO giira cuong dd dong di6n khong ddi r,,a cu'o'ng clo dong di€n cuc dai cua ddng diOn xoay chidu bing
A l B ^[t
Ciu Hai vAt rin A va B c6 mdmen qu6n dQng ndng quay cua A so v6'i B bang
so GrAo Dvc - DAo T4o NAM EINH
Ciu MOt lic vdt ly ld rn6t ddi ( dao d0ng di0u hda xung quanh mdt
mornen qudn tfnh cua d6i vcyi truc quay ld
KV'tHI Hoc sINH GIoI Tllpr roAN rixn
NAM HQC 2008 - 2009 Mdn : Vit ly Lop 12
(Thd'i gian Idm bdi 180 phfit, kh\ng kA thd'i giun gioo tlil Di thi girr 02 trang
c D U "lt
tinh Ia :Zls c6 momen d6ng lu'or-rg La : Ls Ti so
A B ( c.)t t z D "{t
\_ l
Cf,u MQt mach dao d6ng diQn F li tuong LC co chu kj, dao dong dien tu' ri€ng le T D0 lon diQn tfch tr€n ban tu diQn tai tho'i di€m ban dAu birng 112 dd lon diQn tich cr-Lc dai Tho'i gian ngin nhAt tu'lirc ban dAu d6n di6n tfch tr€n bAn tu di€n bang la
A T l B T t r e T ^ D - t
Cnq Me't chAt diOm dao d6ng di€u hda tr€n tr-FOx vo'i bi€n dqt A va chu ky T Quang du'o'ng dai ntrdt rla vAt dao cione di drro-c thoi giar^rTl5 bang
A A",[t. , , , E
@n T
A^12
L - ,
2
r \ n r r l
diri mA,rh, dong chit ti€t truc c6 dinh nim ngang
di€n deu khoi Iu'qng m clrieu va vudng goc vo'i Bi0t t
I= I m.(' Chu k'i dao d6ng cta lac lr)
1 J
D T : n
Ciu MOt vdt rin quay quanh m6t truc cO dinh co phuo'ng trinh g : - - 5t - 2t2 Trong e tfrrlr bdng rad; t tfnh bing giAy G6c quay cua vAt tho'i gian t: giAy ke tir lirc ban dAu barrg
6 t r a d B - r a d C d D r a d CAu Z Mgt ngu6n Arn ph6t rn6t 6m co bAn co tAn s6 f I(hi guong dd 6rn
^ r r J t r \ r r v r ^ ^ r ^
itn bdne ben la L T[ne cuons dd dm l€n 100 l6n thi rnu'c cudns d0 6m dcr
4 L B L c L + 0
Cf,u Hai l6c do'n c6 cuns chidu dai scri d6v dao done di€u goc crl : 2crz N6u hai vAt nlng kTfmf.tq"g t"':-ZmzTht ;n*i
h o a o ' c u n q r n o t n o i v o ' i b i € n d o d a o d o n g c u a c o r r la c c o b i e u
7et
A I : t l -
ls 0r-"!3'W
W
' ' / -V g
r;
c r - o l n
thu'c quan h€ ( f , : T z \_/
la I thi m['c cu'ong blne ben la
( P L + 2
D T r : T t l ' l i .
B T r : T C T r : t l i T z B PruTN TU LI]AIV
,Brii 1 ( 4"0 di6m\ MOt AB dei manh d6ng chdt, ti6t di6n d6u c6 kh6i lu'orrg m, -chi6u cldil,
q u a y q u a r r h , o o t _ t u u , ' o a i n n v u n g g o c v o i t h a i h e i e t m o m e n q , f f i n o T i ' - t ' *
1
(2)l .Khi truc quay di qua trung di6rn cua va dang quay cleu vo'i toc goc 0l tlii dat rlhg mQt vAt nho l€n mdt di€m tr€n rdi dinh chit vaolhantr giet momen quan tfnh csa vet d6i voi truc quay bang l/2 momen qudn tfnh cua tlanh Bo qua rnoi luc cdp Dgns ndns cua h€ tdng hay gi6m bao nhi€u lAn so voi ban diu? t
2 ChAl hd truc toa cl6 Ox cung phu'ong.v6'i thanh, gdc toa dQ O tai trung di€rn cua thanh. Thay doi vi trf cua truc quay dqc it-r.o t'rie., clai cua khAo s61 su'thay"doi 'r-rO r.n qua' tfni-r cua theo toa x cua truc quay'?
4rii 2.- (3.Q di6m) Tai hai dt.t: t yd B tr€n bd rrrdt cua rnot chAt long tinh co hai neLron scinq crr
d a o d o n g < i i e u h o a v o i t a n s d f : H z , c u n g biOn do
l.l-A,^,- +r.^., xi: r,r^: + , ,).,-.=T-62-=;l +?^ , c u n g p h a ban dlu bans Coi
dao d6ng di6u hoa v6i tAn sd f: ?S tlZ cqrg_94L40,
:ung pha bal dlu_ bang 0 Coilte'l dO i,''g
k h r r g t h a y d o i k h i t r u y e n e i l m E - h a t i ] f f i n g c n r / s B i € t k I l c r i i l r g
c c h s i f r ' a h a i n s r r A n l i A R : ) a n ' t
' - - - s - - - e - 1
gi['a lrai nsuot1-[ AB : 12 cm
L Tirn khodng c6ch lon nhElina hai di€m khong dao d6ng,ra,l kho6pg Ail? f l
2 LAy diern N tr€rt be rndt chAt long cho NA I AB va N c6ch A doan x Tim gia tri l n, : r - : I r nh6t cua x d€ phAn tu ch6t long taiX dao clong voi bi€n dd cuc fun- i
@ Hai v'+t.Mr ye M: 19 r<rrol lue'n;',uo,r@ uu
I1l non n1T ngalg cho truc cua lo xo luon thaqg tltmg ( hinh l) Bo qua kh6i .{l o o
lu'gng cua lo xo ldr,v gia toc tru'o'nq/g:_O1li-l ' ' L S I
1 J - i , l " J A l - ; A r ^ ' - , - ^ ' " ^ l : - ' ^ r l - i : f f i ] l ( r ^ ^ F | +
I Tfnh bi€n dang cua lo xo L th-ne can bang? J ,5 }rn
2 Tu'vi trf cAn.bdng nh.an vAt M2 xr6ng Zcm.ttreo phuong thang dune roi tha
nhe kh6ng vdn 1oc dau thi thay vir M3 dao tl6ng di0u hda rrong kii vii-r M' vin nim -r hinr, r) v6n tr6n m[t ben.-Ctgn trqc toa d6 Ox theo phucrng thing dring, chiitu ducmg hu.6ng
xudng gti toa o rel
-v!,rri cin bing cua M2 g5c rhoi gian-ld lric rha v vier ihurmg rrinh tiao
d n r i r r l i ; t X : - < ( L ) q r *
^ ] T q b j : l { O j r " d Q n g I n n h A t c r : r a M C i c h o M l u n l u t ) r r n i r n y € n i r o n g k h r M : d a o o o n g r s , h ^
Brii (6.0 ali€m) Cho mach di€n nhu hinh irong d6 ^ r ) (.
cuon day thuan cdm 90 dO tu cdm L, tu di€n co di€n _rlnninnn_J|]' dung c va R la mot bi€n tro' Ddt vao hai dAu doan mach l-'uYY-Yuv -l
tQn gp j_o'I-_c_!geu 9o dien ap hi€u dung khOng d6i I I rt
/ r - - \ l
I u : 100 "12 cos I 00nt (V).\ |
I A B
^ - ?
I t l t
-L C h o -L
TE 5n - /
a) Di€u chinh bi€n tro'dd R:50 fi Viet bidu thu'c diqn 6p hai dAu tu di€n? ln q(kn(7 t g) b) Di6u chinh bi€n tro'd6 cdng su6t tiOu thu cua do4rr mach bdng 100 W Tim di€p rro.R cjo?
- , T t r ^
2- I'hay doi gi6 triL va C tot gi6'trixac dinh rdi di€u chinh gi6tri cua bi6p trii' Tim cli6n ap hi€u dUng lon nhAt gifi'a hai di6m M vd N theo ll: Zr; Zg vd R? Xet c6c rruo.ng hop LC.d < va LCco2 >
Biii (2,0 dj6-) Mgt mach p Sgrlg-,Aie" tu' li' tu'ong LC gorn cuon day co tu' capr
!;*|q+il.S diqn co di€n aun\-r- y!)x6i nai bantq di€n vo'i hai cu'c cua nguon di€n khong
d6l.Tai tho'i diOrl t - 0, ngdt nguo,i.a-kh-6i ru clien roi noi'z ban tu di€n voi trai d-a, ;;i a,r-, jE
trong.mach co dao dOng di€n til'ri6ng l'irn khodng tho'i gian ngSn nh6t tu' luc nOi hui bAn ru di€n 'o'i hai ddu cu6n cAm d€n nang luo'ng dien tru'onglAp trung trJng tu Oier't t a"g
"a"-* f "n'r*ly.,ir.tr,rg tap trung cudn chn-r? Trong khoang tho'i gian ndng.luo.ng^di€n tru'o'ng nang lrro-ng ru.tru.o.re vd ndng lugng cli€n tu'cua mach thay ddi nhu'th€ ndo? 1,9 tu s
l ) - ) A : C ,
t , - l ,
u - L ' c
- ) L - ) r
*n Ur^ nd l)
Lccr'<t 0"L rk
Ho va t6n rhi sinh: Ctrfr' ky cua giarn rtri so | ,C.gp/: ,,i!.l F- fr.^
2 _1 -L l*c tt