Tm tt l thuyt vt l 12 n thi i hc luyn thi i hc BNG TM TT L THUYT VT L 12 ( Nng cao)

CHNG I: NG LC HC VT RN I. c im chuyn ng ca vt rn quay quanh 1 trc c nh:

Mi im vch ra mt ng trn nm trong mt phng vung gc vi

trc quay c bn knh bng khong cch t im n trc quay.

Mi im trn vt u quay c cng 1 gc trong cng 1 khong thi

gian.

II. nh lut bo ton momen ng lng:

Mmen ng lng: .L I

nh l bin thin momen ng lng: L = M.t

Nu tng cc momen lc tc dng ln mt vt rn (hay h vt) i vi

trc quay bng khng th tng momen ng lng ca vt rn (hay h

vt) i vi 1 trc c bo ton

L = hng s

III. Momen qun tnh ca vt rn i vi mt trc quay:

N: L i lng c trng cho mc qun tnh ca vt rn trong chuyn ng

quay quanh trc y.

Thanh di c trc quay i qua trng tm: 21

12I ml

Thanh di c trc quay i qua u thanh: 2

3

1mlI

Vnh trn bn knh R (hnh tr rng) : I = mR

a trn mng (hnh tr c): 21

.2

I m R

Khi cu c, trc quay i qua tm: 22

.5

I m R

IV. Tc gc:

N: Tc gc tc thi (tc gc) l i lng c trng cho mc

nhanh, chm ca chuyn ng quay ca vt rn quanh mt trc thi

im t v c xc nh bng o hm ca to gc theo thi gian.

V. Gia tc gc:

N: Gia tc gc tc thi (gia tc gc) ca vt rn quay quanh mt trc c

nh thi im t l i lng c trng cho s bin thin ca tc gc

thi im v c xc nh bng o hm ca tc gc theo thi

gian

VI. Cc cng thc trong chuyn ng quay

Cc cng thc ca chuyn ng quay bin i u ( = const)

.2

2

1

22

2

o

o

o

tt

t

Phng trnh c bn chuyn ng quay ca vt rn:

.M I

ng nng quay: W 21

.2

I

Mi lin h gia tc gc, tc di: v = .R

Mi lin h gia gia tc gc v gia tc tip tuyn: R

Tm tt l thuyt vt l 12 n thi i hc luyn thi i hc

CHNG II: DAO NG C CC KHI NIM C BN C IM CA VN TC V GIA TC TRONG DAO NG IU

HO

Dao ng: l qu trnh chuyn ng qua li quanh mt v tr cn bng.

Dao ng tun hon: l dao ng m trng thi dao ng c lp li nh c sau nhng khong thi gian bng nhau.

Dao ng iu ho: l dao ng m phng trnh c dng l hm sin hay cos ph thuc thi gian nhn vi 1 hng s. c im: + L hnh chiu ca chuyn ng trn u

xung ng thng trong mt phng qu o. + Mi dao ng iu ho iu ho c biu

din bng mt vect quay. + Bin dao ng A ph thuc vo iu kin

ban u Dao ng t do: l dao ng ca 1 h chu nh hng ca ni

lc. c im: Chu k ca dao ng ph thuc c im ca h.

Dao ng tt dn: l dao ng c bin gim dn theo thi gian. c im: + ph thuc vo ma st.

+ ph thuc vo bin . + khng phi l dao ng iu ho. + ph thuc vo nht.

Dao ng duy tr l dao ng tt dn c duy tr bng cch gi cho bin v tn s khng thay i. c im: + Bin A khng i.

+ tn s dao ng bng tn s dao ng ring. Dao ng cng bc: l dao ng chu tc dng ca ngoi lc tun

hon.

c im: + Dao ng cng bc l dao ng iu ho. + tn s gc ca dao ng cng bc bng tn

s gc ca ngoi lc. + Bin ca dao ng cng bc ph thuc

bin ca ngoi lc v chnh lch tn s ca ngoi lc v tn s dao ng ring ca h.

Chu k: l thi gian thc hin 1 dao ng ton phn. Tn s: l nghch o ca chu k.

Vn tc: + v sm pha hn x mt gc 2

+ v i chiu khi qua v tr bin + v bng 0 khi v tr bin

+ v t cc i bng A khi vt qua VTCB.

Gia tc: + a vi x ngc pha + a tri du vi x + a bng 0 khi VTCB, c ln cc i khi v tr

bin + a lun c hng v VTCB + ln a t l vi ln x

Lc hi phc: + lun hng v VTCB + ln t l vi lch khi VTCB + cc i khi vt v tr bin .

Tm tt l thuyt vt l 12 n thi i hc luyn thi i hc

CHNG III: SNG C HC

I. SNG C: 1. nh ngha: Sng c hc l s lan truyn ca dao ng c hc trong mt mi trng vt cht n hi. 2. Tc truyn sng: l i lng c trng cho s lan truyn

nhanh hay chm ca sng v ch ph thuc bn cht mi trng.

3. Bc sng: (KH: ) - L qung ng sng truyn c trong mt chu k. - L khong cch gia 2 im gn nhau nht trn phng truyn sng m dao ng ti 2 im l cng pha. * ngha: + nhng im cch nhau s nguyn ln bc sng th dao ng cng pha. + nhng im cch nhau 1 s bn nguyn ln bc sng th dao ng ngc pha.

4. Sng ngang: l sng m cc phn t ca mi trng dao ng theo phng vung gc vi phng truyn sng. * MTrng truyn: cht rn, trn b mt cht lng.

5. Sng dc: l sng m cc phn t ca mi trng dao ng theo phng truyn sng. * Mtrng truyn: rn, lng, kh.

6. Phn x sng: sng ang truyn trong mt mi trng m gp vt cn th b phn x. *Tnh cht: + c cng tn s v bc sng i vi sng ti. + Vt cn c nh: sng px ngc pha sng ti. + Vt cn t do: sng px cng pha sng ti.

II. SNG DNG: 1. N: Sng dng l sng c cc nt v cc bng c nh trong

khng gian.

2. iu kin xy ra sng dng: * u phn x sng c nh:

l = k.2

S nt = k+1; S bng = k

* u phn x sng t do:

l = (k+2

1).

2

S nt = S bng = k+1

III. GIAO THOA SNG: 1. N: Giao thoa sng l hin tng 2 sng kt hp, khi gp nhau ti nhng im

xc nh, lun lun hoc tng cng nhau hoc trit tiu nhau. 2. iu kin: hai sng phi xut pht t hai ngun dao ng c cng tn s, cng

phng dao ng v c lch pha khng i theo thi gian.

3. lch pha ca hai ngun sng: 2 1

2( )d d

* Bin dao ng cc i (cng pha): 2k

* Bin dao ng cc tiu: (2 1)k .

IV. SNG M: 1. N: Sng m l nhng sng c truyn trong cc mi trng rn, lng, kh. 2. Mi trng truyn sng:

+ Trong cht lng v cht kh sng m l sng dc. + Trong cht rn sng m gm c sng ngang v sng dc. Tc truyn m: ph thuc vo nhit , khi lng ring ca mi trng.

3. c trng sinh l ca m: - cao: l c trng sinh l ca m t l vi tn s f ca m. + Nhng m c f > 20.000 Hz gi l siu m. + Nhng m c f < 16 Hz gi l h m. - m sc: l c trng sinh l ca m ph thuc bin v tn s gip phn bit hai m thanh c cng m c bn nhng do hai ngun m khc nhau pht ra. - to ca m: Ph thuc cng m v mc cng m.

+ Cng m: 24 R

PI n

+ Mc cng m c nh ngha bng cng thc: 0

( ) lgI

L BI

.

4. Hiu ng p-Ple: * KN: l hin tng tn s sng m m ngun thu nhn c f khc vi tn s sng m do ngun pht ra f khi ngun m v my thu c chuyn ng tng i.

a). Ngun m ng yn, my thu chuyn ng:

* Tn s: ' .M MV V V V

f fV

( Du - nu ngun di chuyn ra xa) b). My thu ng yn, ngun m chuyn ng.

* Ngi quan st: ' .' S

V Vf f

V V

(du - nu dch chuyn li gn).

Tm tt l thuyt vt l 12 n thi i hc luyn thi i hc CHNG IV: DAO NG IN T

I. MCH DAO NG 1.Khi nim mch dao ng: l mch in kn gm cun cm L v t in C.

2.S bin thin q, u, i: Biu thc:

q = Qocos(t+); u = C

Q

C

q o cos(t+); i = q = - Qosin(t+);

c im:

* i sm pha hn q mt lng 2

* u,q cng pha

* q bin thin iu ho Nhn xt: i, q, u bin thin iu ho.

3.Nng lng in trng trong mch dao ng:

Biu thc: EC

Q

C

q

22

2

0

2

cos2(t+); Et = C

QLi o

22

12

2 sin2(t+)

c im: E v Et bin thin iu ho vi tn s =2 nhng tng ca chng l nng lng in t khng thay i.

4. Cc nh ngha:

Dao ng in t duy tr: l dao ng c duy tr vi tn s dao ng ring fo bng cch b ng phn nng lng b tiu hao trong mi chu k.

Dao ng in t tt dn: l dao ng in t c bin gim dn n 0, gi tr R rt ln th khng c dao ng.

Dao ng in t cng bc: l dao ng in trong mch dao ng theo tn s f ca ngun (thng thng f fo)

S cng hng: L hin tng bin ca dao ng in t t gi tr cc i khi f = fo

II. IN T TRNG: 1. Khi nim in t trng * in trng v t trng bin thin cng tn ti trong khng gian chuyn ho ln nhau trong mt trng thng nht gi l in t trng. * c im: + in trng hay t trng l tng mt ca mt chnh th in t trng + Khng bao gi c s tn ti ring bit ca in trng hay t trng c 2. Cc gi thuyt MC-XOEN: * T trng bin thin theo thi gian lm xut hin in trng xoy. (c im in trng xoy l ng sc ca n khng c im khi u v cng khng c im kt thc nh ng sc ca in trng tnh m l ng cong kn).

* in trng bin thin theo thi gian lm xut hin t trng xoy. (Cc ng sc ca t trng ny l cc ng khp kn bao quanh cc ng sc ca in trng)

III.SNG IN T: 1.nh ngha: Sng in t l qu trnh lan truyn in t trng trong khng gian. 2. c im: * Tc lan truyn ca sng in t trong chn khng bng tc nh sng c = 300000 km/s

* Sng in t l sng ngang. Vect cng in trng lun vung gc vi vect

cm ng t v c 2 lun vung gc vi phng truyn sng. C E v B u bin thin tun hon theo khng gian v thi gian, v lun ng pha * Sng in t c th truyn qua c chn khng 3. Tnh cht ca sng in t: * Trong qu trnh lan truyn, n mang theo nng lng. * Tun theo cc quy lut truyn thng, phn x v khc x. * Tun theo cc quy lut giao thoa, nhiu x. IV.S TRUYN THNG: 1. Mch dao ng h: l mch dao ng m in t trng bc x ra bn ngoi. 2. Mch dao ng kn: l mch dao ng m in t trng khng bc x ra ngoi. 3. Anten: l 1 dng mch dao ng h l 1 cng c hu hiu bc x sng in t. 4. Nguyn tc chung ca s truyn thng bng sng in t:

+ Bin cc m thanh (hnh nh) mun truyn i thnh cc dao ng in tn s thp (tn hiu m tn). + Dng sng in t tn s cao mang cc tn hiu m tn i xa qua anten pht. + Dng my thu vi anten thu chn v thu ly sng in t cao tn. + Tch tn hiu m tn ra khi sng cao tn v a ra loa.

H thng pht thanh: + Dao dng cao tn: to ra dao dng in t tn s cao (MHz) + ng ni: bin m thanh thnh dao ng in m tn. + Bin iu: trn dao ng m thanh v dao ng cao tn thnh dao ng cao tn bin iu. + Khuch i cao tn: khuch i dao ng cao tn bin iu a ra anten pht.

+ Anten pht: pht x sng cao tn bin iu ra khng gian. H thng thu thanh:

+ Anten thu: cm ng nhiu vi sng in t. + Chn sng: chn lc sng mun thu nh cng hng. + Tch sng: ly ra sng m tn t sng cao tn bin iu thu c. + Khuch i m tn: khuch i m tn ri a ra loa ti lp m thanh.

CHNG V: DNG IN XOAY CHIU I. MY IN

1. My pht in xoay chiu: Nguyn tc hot ng: da trn hin tng cm ng in t: khi t thng qua

mt vng dy bin thin iu ho, trong vng dy xut hin sut in ng cm ng xoay chiu .

Gii thch: Nu t thng qua mi vng dy bin thin thin v trong cun dy c N vng ging nhau, th xut hin sut in ng xoay chiu trong cun dy.

My pht in xoay chiu 1 pha: Cu to: c 2 b phn chnh l:

Phn cm: l phn to ra t trng c th l nam chm in hoc nam chm vnh cu.

Phn ng: l nhng cun dy trong xut hin sut in ng cm ng khi my hot ng.

Phn c nh l stato, phn quay l roto. Hot ng:

Cch 1: phn ng quay, phn cm c nh. * Stato l nam chm t c nh, roto l khung dy quay quanh 1 trc trong t trng to bi stato. * dn dng in ra mch ngoi, dng 2 vnh khuyn t ng trc & cng quay vi khung dy. Mi vnh khuyn c 1 thanh qut t vo. Khi khung dy quay, 2 vnh khuyn trt trn 2 thanh qut ,dao ng truyn t khung dy qua 2 thanh qut ra ngoi.

Cch 2: phn cm quay,phn ng c nh. -Cn roto l nam chm in c nui bi dng in 1 chiu, stato gm nhiu cun dy c li st xp thnh 1 vng trn.

My pht in xoay chiu 3 pha: l h thng 3 dng in xoay chiu gy bi 3 sut in ng xoay chiu c cng tn s bin nhng lch pha nhau tng i mt v

bng 2

3

.

Cu to: stato c 3 cun dy ring r, hon ton ging nhau, qun trn 3 li st t lch nhau 120 trn 1 vng trn. Roto l 1 nam chm in.

Nguyn tc hot ng: khi roto quay u cc sut in ng cm ng

xut hin trong 3 cun dy c cng bin , cng tn s nhng lch pha nhau l 2

3

.

Nu ni cc u dy ca 3 cun vi 3 mch ngai ging nhau th ta c h 3 dng in

cng bin , cng tn s nhng lch pha nhau v pha l 2

3

Cng thc tnh: f = p.n (p: S cp cc, n: S vng quay trong 1s)

2. ng c khng ng b 3 pha: Nguyn tc hot ng: * Da trn hin tng cm ng in t

*Tc dng ca t trng quay.

Cu to: Stato c 3 cun dy ging nhau qun trn 3 li

st b tr lch nhau 1/3 vng trn. Roto l 1 hnh tr to bi nhiu l thp mng

ghp cch in vi nhau, cc rnh x mt ngoi roto c t cc thanh kim loi. Hai u mi thanh c ni vo cc vnh kim loi to thnh mt chic lng. Lng ny cch in vi li thp v c tc dng nh nhiu khung dy u t lch nhau to thnh roto lng sc.

Hot ng: Khi mc cc cun dy stato vi ngun in 3 pha t trng quay to thnh c tc gc bng tn s gc ca dng in. T trng quay tc dng ln dng in cm ng trong khung dy roto lm roto quay vi tc nh

hn tc gc quay ca t trng cun s cp.

+ Cun 2 ni vi ti tiu th in nng bng>th cp. Hot ng: Da trn hin tng cm ng in t * Gii thch: +Dng in qua cun s cp bng>xut hin t trng bin thin + T thng bin thin cun th cp lm xut hin

cun th cp sut in ng xoay chiu.

Cng thc: 2

1

2

1

N

N

U

U ;

11

22

IU

IU

P

PH

vao

ra

CHNG VI. SNG NH SNG I. TN SC NH SNG

1. nh sng trng: l tng hp v s nh sng n sc c mu bin thin lin tc t n tm.

2. nh sng n sc: l nh sng khng b tn sc m ch b lch khi i qua lng knh.

3. S tn sc nh sng l s phn tch mt chm nh sng phc tp thnh cc chm nh sng n sc khc nhau.

4. Gii thch hin tng tn sc nh sng: * Chit sut ca thu tinh c gi tr khc nhau i vi nh sng n sc c mu khc nhau, gi tr nh nht i vi nh sng v ln nht i vi nh sng

tm. * Gc lch ca tia sng qua lng knh ph thuc vo chit sut ca lng knh. Chit sut cng ln th gc lch cng ln.

II. NHIU X NH SNG V GIAO THOA NH SNG. 1. Nhiu x nh sng l hin tng nh sng khng tun theo nh lut truyn

thng, quan st c khi nh sng truyn qua l nh hoc gn mp cc vt trong sut hoc khng trong sut.

2. Giao thoa nh sng l hin tng khi hai chm sng kt hp (cng tn s v c lch pha khng i) gp nhau to nn cc vn sng v vn ti xen k cch u nhau.

III. KHONG VN, BC SNG V MU SC NH SNG. 1. Khong vn (i) l khong cch gia hai vn sng (hoc ti) cnh nhau

Di

a

.

V tr vn sng : D

x ka

V tr vn ti : ( 0,5)D

x ka

.

2. Bc sng v mu sc nh sng: Mi nh sng n sc c mt bc sng xc nh v tn s f xc nh. Mi nh sng n sc m ta nhn thy c 0,38 m 0,76 m

(: = 0,76 m; tm: = 0,38 m). 3. Chit sut ca mi trng: Chit sut n ca mi trng trong sut i vi mt nh sng n sc ph thuc

vo tn s ca nh sng n sc .

Chit sut ca mi trng : c

nv

; ( )F f

Trong : c : vn tc nh sng trong chn khng v : vn tc nh sng trong mi trng c t thm v hng s in mi f : tn s ca nh sng

IV. MY QUANG PH LNG KNH. My quang ph l dng c dng phn tch chm

sng phc tp thnh nhng thnh phn n sc khc nhau.

My quang ph lng knh gm 3 b phn chnh : ng chun trc, h tn sc, bung nh.

Nguyn tc hot ng : da trn hin tng tn sc nh sng.

V. TIA HNG NGOI, T NGOI, TIA RNGHEN.

VI. CC LOI QUANG PH.

Xem tip trang bn

Tm tt l thuyt vt l 12 n thi i hc luyn

thi i hc

Tia hng ngoi Tia t ngoi Tia X QP Vch lin tc

QP Vch pht x

QP Vch hp th

nh

ngh

a

L bc x c bc sng di hn 0,76 m n vi mm (ln hn bc sng ca nh sng v nh hn bc sng ca sng v tuyn in)

Bc x c bc sng ngn hn 0,38 m n c 10-9 m (ngn hn bc sng ca nh sng tm)

Bc x c bc sng t 10

-8m 10

-11m (ngn hn

bc sng tia t ngoi)

L QP gm nhiu di mu t n tm, ni lin nhau mt cch lin tc

L QP gm cc vch mu ring l, ngn cch nhau bng nhng khong ti.

C dng cc vch ti trn nn ca quang ph lin tc.

Ngu

n

ph

t Mi vt mi

nhit (T>0 K); l than, l in, n dy tc

Ch :

Tvt>Tmi trng

Cc vt b nung nng n trn 2000oC; n hi thy ngn, h quang in c nhit trn 3000

oC

Khi cho chm tia catot c

vn tc ln p vo mt i m cc bng kim loi kh nng chy nh vonfam hoc platin

Cc cht rn, cht lng v cht kh p sut ln b nung nng.

Cc cht kh hay hi p sut thp b kch thch nng sng.

Khi chiu nh sng trng qua m kh hay hi kim loi c nhit thp hn nhit ngun sng s to ra quang ph hp th.

Tn

h c

ht

* Tc dng nhit * Gy ra mt s phn ng ha hc * C th bin iu c nh sng cao tn *Gy ra hin tng quang in trong mt s cht bn dn

* Tc dng ln phim nh * Lm ion ha khng

kh

* Gy ra phn ng quang ha, quang hp * Tc dng sinh l: hy dit t bo da, dit khun * Gy ra hin tng quang in * B nc v thy tinh hp th rt mnh

* Kh nng m xuyn. Tia X c bc sng cng ngn th kh nng m xuyn cng mnh, c th xuyn qua cc vt chn sng thng thng. * Tc dng mnh ln phim nh, lm ion ha khng kh. * Tc dng lm pht quang nhiu cht. * Gy ra hin tng quang in hu ht kim loi. * Tc dng dit vi khun, hy dit t bo.

* Khng ph thuc bn cht ca vt, ch ph thuc nhit ca vt. * mi nhit , vt u bc x. * Khi nhit tng dn th cng bc x cng mnh v min quang ph lan dn t bc x c bc sng di sang bc x c bc sng ngn.

Nguyn t khc nhau c quang

ph vch ring khc nhau v s lng vch, mu sc vch, v tr vch v cng sng ca vch.

- mt nhit xc nh, vt ch hp th nhng bc x m n c kh nng pht x, v ngc li. - Cc nguyn t khc nhau c QP vch hp th ring c trng cho nguyn t .

n

g d

n

g

* Sy kh, si m * iu khin t xa

* Chp nh b mt Tri t t v tinh * Qun s (tn la t ng tm mc tiu, camera hng ngoi, ng nhm hng ngoi)

* Kh trng nc ung, thc phm * Cha bnh ci xng * Xc nh vt nc trn b mt kim loi

* Chiu in, chp in dng trong y t chn on bnh. * Cha bnh ung th. * Kim tra vt c, d bt kh, vt nt trong kim loi. * Kim tra hnh l hnh khch i my bay.

o nhit ca vt Xc nh thnh phn (nguyn t), hm lng cc thnh phn trong vt.

CHNG VII. LNG T NH SNG I. HIN TNG QUANG IN NGOI.

1. Khi nim: Hin tng quang in ngoi l hin tng nh sng lm bt cc electron ra khi b mt kim loi. * Cc electron b bt ra gi l electron quang in hay quang electron

2. Cc nh lut quang in:

nh lut v gii hn quang in: Hin tng quang in ch xy ra khi nh sng kch thch chiu vo kim loi c bc sng nh hn

hoc bng gii hn quang in ca kim loi . 0 ( 0 nm trong

min t ngoi).

nh lut v cng dng quang in bo ha: i vi mi nh

sng thch hp (c 0 ), cng dng quang in bo ha t l

thun vi cng ca chm sng kch thch.

nh lut v ng nng cc i ca quang electron: ng nng ban u cc i ca quang electrong khng ph thuc cng ca chm sng kch thch, m ch ph thuc bc sng nh sng kch thch v bn cht ca kim loi.

II. THUYT LNG T NH SNG. 1. Gi thuyt Plng:

Nguyn t hay phn t khng hp th hay pht x nh sng mt cch lin tc m thnh tng phn ring bit t qun, mi phn c gi tr hon ton xc nh hf , gi l lng t nng lng.

2. Thuyt lng t nh sng: Chm nh sng l mt chm cc photon (cc lng t nh sng). Mi

photon c nng lng xc nh hf . Cng ca chm sng t l

vi s photon pht ra trong 1s (giy). Phn t, nguyn t, electron pht x hay hp th nh sng cng c

ngha l chng pht x hay hp th photon. Cc photon bay dc theo tia sng vi tc c = 3.108m/s trong chn

khng.

III. HIN TNG QUANG IN TRONG 1. Hin tng quang in trong l hin tng to thnh cc electron dn

v l trng trong cht bn dn, do tc dng ca nh sng c bc sng thch hp.

* iu kin: 0 ( 0 nm trong vng nh sng hng ngoi).

2. Hin tng quang dn l hin tng gim in tr sut, tc l tng dn in ca bn dn, khi c nh sng thch hp chiu vo bn dn.

3. Quang in tr :

L tm bn dn c gi tr in tr thay i khi cng chm sng chiu vo n thay i.

Nguyn tc hot ng: da trn hin tng quang in trong.

Cu to: gm mt tm bn dn c gn hai in cc.

ng dng: c lp vi cc mch khuch i trong cc thit b iu khin bng nh sng, trong cc my o nh sng.

4. Pin quang in.

L ngun in trong quang nng c bin i trc tip thnh in nng.

Nguyn tc hot ng: da trn hin tng quang in trong ca mt s cht bn dn nh ng oxit, selen, silic..

Cu to: gm 1 tm bn dn loi n, bn trn c ph lp mng bn dn loi p. Mt trn cng l 1 lp kloi mng, trong sut vi nh sng v di cng l 1 kim loi.

ng dng: ngun in cho vng su, vng xa, hi o, v tinh nhn to, my o nh sng, my tnh b ti

IV. HP TH NH SNG. 1. Hp th nh sng l hin tng mi trng vt cht lm

gim cng ca chm sng truyn qua n. 2. nh lut v s hp th nh sng: Cng I ca chm

sng n sc, khi truyn qua mi trng hp th, gim theo nh lut hm m ca di d ca ng i tia sng.

0

dI I e ; 0I l cng chm sng ti mi trng; l

h s hp th ca mi trng.

Tm tt l thuyt vt l 12 n thi i hc luyn thi i hc

V. TIN BO. 1. Nguyn t ch tn ti trong mt s trng thi c nng lng xc nh En,

gi l trng thi dng. Khi trng thi dng, nguyn t khng bc x. 2. Tin v s hp th v bc x nng lng ca nguyn t. Khi nguyn t chuyn t trng thi dng c mc nng lng EN sang

trng thi dng c mc nng lng EM nh hn th nguyn t pht ra mt photon c nng lng hfbng EN - EM.

Khi nguyn t ang trng thi dng c mc nng lng EM m hp th mt photon c nng lng hf bng EN - EM th n chuyn sang trng thi dng c mc nng lng EN ln hn.

3. Quang ph ca nguyn t Hidro. c im: Sp xp thnh cc dy khc nhau:

Dy Laiman nm trong vng t ngoi.

Dy Banme: 1 phn nm trong vng t ngoi, 1 phn nm trong nh sng nhn thy: , lam , chm , tm .

Dy Pasen: trong min hng ngoi. Gii thch:

S to thnh quang ph vch: + Khi nhn c nng lng kch thch, nt hiro chuyn ra

qu o bn ngoi. + Khi chyn t qu o bn ngoi v trng thi c bn, cc

nt hiro pht ra cc phtn bng> Quang ph vch.

S to thnh cc dy: + Laiman: to thnh khi e chuyn t qu o bn ngoi vo k. + Banme: to thnh khi e t cc qu o pha ngoi chuyn v

qu o L: M bng> L (vch ), N bng> L (vch lam), O bng> L ( vch chm), P bng> L (vch tm)

+ Pasen: c to thnh khi e t qu o ngoi chuyn v qu o M.

VI. S PHT QUANG. 1. S pht quang l hin tng m mt s cht (rn, lng, kh) hp th

nng lng di mt dng no th pht ra cc bc x in t trong min nh sng nhn thy * c im:

Mi cht pht quang c mt quang ph c trng cho n.

Sau khi ngng kch thch, s pht quang ca mt s cht vn cn tip tc ko di thm mt khong thi gian no ri mi dng hn..

2. Cc dng pht quang:

Hunh quang l s pht quang c thi gian pht quang ngn (di 10-8s; hu nh tt ngay sau khi ngng kch thch). Thng xy ra vi cht lng v cht kh.

Ln quang l s pht quang c thi gian pht quang di (10

-8s tr ln). Thng xy ra vi cht rn (cht ln quang).

3. nh lut Xtc v s pht quang: nh sng pht quang c bc sng ' di hn bc sng ca nh sng kch thch: ' > .

VII. S LC V LAZE. Laze l mt ngun pht ra chm sng song song, kt

hp, c tnh n sc rt cao v c cng ln.

Cc loi laze: laze hng ngc, laze rn, laze kh, laze bn dn.

ng dng: thng tin lin lc v tuyn; dao m, cha bnh ngoi da; u c CD, bt tr bng; khoan, ct.

Tm tt l thuyt vt l 12 n thi i hc luyn thi

i hc

CHNG VIII. S LC V THUYT TNG I HP

I. THUYT TNG I HP. 1. Tin Anh-xtanh.

Tin I: cc nh lut vt l (c hc, in t hc..) c cng mt dng nh nhau trong mi h quy chiu qun tnh.

Tin II: Tc nh sng trong chn khng c cng ln bng c trong mi h quy chiu qun tnh, khng ph thuc vo phng truyn v vo tc ca ngun sng hay my thu. c = 300 000 km/s.

2. H qu thuyt tng i hp.

S co di: 2

0 21

vl l

c

Trong : 0l : di ring, l : di quan st.

S chm li ca ng h chuyn ng: 0 02

21

tt t

v

c

.

II. H THC ANH-XTANH. 1. Khi lng tng i tnh.

00

2

21

mm m

v

c

.

Trong : m: l khi lng tng i tnh, m0: khi lng ngh ca vt. 2. H thc gia nng lng v khi lng.

2 20

2

21

mE mc c

v

c

.

Khi nng lng thay i mt lng E th khi lng thay i mt lng m tng ng v ngc li.

E = m .c2. Cc trng hp ring:

+ Khi v = 0 th 20 0 0.E m c E : Nng lng ngh.

+ Khi 1c

vth: 2 20 0

1

2E m c m v .

3. ng lng v ng nng ca vt trong c hc tng

i tnh. ng lng:

p = m.v = v

c

v

mo

2

2

1

ng nng:

)1

1

1(

2

2

2

c

vcmEEW ood

Tm tt l thuyt vt l 12 n thi i hc

luyn thi i hc

CHNG IX. HT NHN NGUYN T

I. CU TO HT NHN NGUYN T. 1. Cu to ht nhn:

Ht nhn: c cu to t nhng ht nh hn gi l nucln. C 2 loi nucln:

+ Prtn (p): c mp = 1,67262.10-27

kg, mang in tch nguyn t dng.

+ Ntron (n): c mn = 1,67493.10-27

kg, khng mang in.

S prtn trong ht nhn bng s th t Z. S ntron trong ht nhn: N = A-Z vi A l s khi (tng s nucln).

Kch thc ht nhn: R = 1,2.10-15A-1/3(m). 2. ng v:

ng v l nhng nguyn t m ht nhn cha cng s prtn Z, nhng c s ntron N khc nhau.

3. n v khi lng nguyn t: 1u = 1,6605.10-27kg = 931,5MeV/c2.

4. Nng lng lin kt: Lc ht nhn: l lc tng tc gia cc nucln trong ht nhn.

c im: + Khng phi l lc tnh in, khng f thuc vo in tch ca cc nucln, c cng rt ln. + Ch c tc dng khi 2 nucln cch nhau 1 khong rt ngn bng hoc nh hn kch thc ca ht nhn. + Mun tch nucln ra khi ht nhn cn fi tn nng lng thng lc ht nhn.

ht khi:

.( )p N h nhanm Zm A Z m m .

Nng lng:

2 2

0 ( ) .p nE Zm A Z m c m c .

Nng lng lin kt: L do mang tn nng lng lin kt:

+ C nng lng to ra khi to thnh ht nhn. + Mun tch ht nhn thnh cc nucln ring r cn tn nng lng.

Nng lng lin kt tnh cho 1 nucln gi l nng lng lin kt ring.

+ c im: c trng cho bn vng ca ht nhn + Ht nhn c nng lng lin kt ring cng ln th cng bn vng.

2 2.. ( ) .lk p n h nhanW m c Zm A Z m m c .

II. PHNG X. 1. Hin tng phng x l hin tng m mt ht nhn

khng bn vng t pht ra cc tia phng x v bin i thnh ht nhn khc. c im: do nguyn nhn bn trong gy ra khng

ph thuc cc yu t bn ngoi. Qu trnh phn r phng x l qu trnh chnh dn

n s bin i ht nhn. Ht nhn phng x l ht nhn m. Ht nhn sn

phm phn r l ht nhn con.

2. Cc loi tia phng x. Tia

Chnh l cc ht nhn ca nguyn t Heli.

Tc khong 2.107m/s, lm ion ho mnh cc nguyn t trn ng i ca n nn mt nng lng rt nhanh.

i c ti a khong 8cm trong khng kh, khng xuyn qua t ba dy 1mm.

B lch trong t trng v in trng. Tia

Vn tc xp x vn tc nh sng.

Lm ion ha mi trng yu hn tia .

i c qung ng di hn vi mt trong khng kh v c th xuyn qua l nhm c mm.

+ - chnh l cc electron e .

+ + chnh l cc pozitron e .

* Ntrino() v phn notriono ( ) l cc ht khng mang in, khi lng ngh bng 0, vn tc xp x vn tc nh sng.

Tia

L sng in t c 1110 m , cng l ht photon c nng lng rt cao.

Kh nng m xuyn rt ln.

Trong phn r v , ht nhn con c th trng thi kch thch v phng x tia tr v trng thi c bn.

CHNG X: T VI M N V M I. CC HT S CP:

1. Ht s cp: l cc ht c kch thc v khi lng rt nh, nh hn ht nhn nguyn t.

2. Cc c trng: * Khi lng ngh mo hoc thay cho mo ngi ta thng dng i lng c trng l Eo = mo.c

2.

* in tch: Q = +1, Q = 0, Q = -1. (Q: s lng t in tch) * Spin l i lng c trng cho momen ng lng ring v

mmen t ring ca ht. ( )2

hs

.

* Thi gian sng trung bnh: c 4 ht khng phn r thnh cc ht khc ( ht bn): prtn, lectron, phtn, ntrin. Tt c cc ht cn li l cc ht khng bn tr ntron c thi gian sng khong 932s.

3. Phn ht: * Phn ln cc ht s cp to thnh cp: ht v phn ht. C khi lng ngh mo nh nhau, mt s c trng khc th c tr s bng nhau nhng tri du. * Trong qu trnh tng tc ca cc ht, c th xy ra hin tng hu mt cp ht + phn ht thnh cc ht khc, hoc sinh ra 1 cp ht v phn ht.

4. Phn loi * Phton: c mo bng 0. * Leptn: gm lectron, muyn, cc ht tau. * Mzn: gm cc ht c khi lng trung bnh: mzn v mzn k.

* Barion: gm cc ht nng c khi lng mp.C 2 nhm: nucln v hipron, cng cc phn ht ca chng. Tp hp cc mzn v barion c tn chung l harn.

5. Tng tc ca cc ht s cp * Tng tc hp dn: tng tc gia cc ht vt cht c khi lng. * Tng tc in t: tng tc gia cc ht mang in, ma st...

* Tng tc yu: tng tc gia cc ht trong phn r . * Tng tc mnh: l tng tc gia cc harn.

6. Ht quac * Tt c cc harn u cu to t cc ht nh hn, gi l quac.

* C 6 ht quac: u, d, s, c, b v t. in tch cc ht quac v phn

quac bng 2

,3 3

e e .

* Cc barion l t hp ca 3 quac (VD: ntron udd; proton uud)

II. MT TRI V H MT TRI 1. Cu to h Mt Tri.

a) H Mt Tri bao gm:

Mt Tri trung tm h ( l thin th duy nht nng sng)

Tm hnh tinh ln: Thu Tinh, Kim tinh, Tri t, Ho tinh, Mc tinh, Th tinh, Thin Vng tinh v Hi Vng tinh.

Cc hnh tinh t hon: gi l cc tiu hnh tinh, cc sao chi, thin thch

b) c im:

Tt c cc hnh tinh u chuyn ng quanh Mt Tri theo cng 1 chiu thun, gn nh trong cng 1 mt phng.

Mt tri v cc hnh tinh u quay quanh mnh n v theo chiu thun (tr Kim tinh).

Ton b h Mt Tri quay quanh trung tm Thin H ca chng ta.

T nh lut III K-ple, khi lng ca Mt Tri ln hn khi lng Tri t 333 000 ln (1,99.1030 kg).

2) Mt Tri. a) Cu to: gm 2 phn quang cu v kh quyn.

Quang cu: c dng a sng trn vi bn knh gc 16 pht. + Khi lng ring trung bnh ca vt cht trong quang cu l 1400kg/m

3.

Kh quyn Mt Tri: + Cu to ch yu bi Hiro, Heli + Phn lm 2 lp: sc cu v nht hoa. - Sc cu: l lp kh nm st mt quang cu c dy trn 10000 km, nhit khong 4500K. - Nht hoa: nm pha ngoi sc cu, vt cht cu to trng thi ion ho mnh (trng thi plasma).

a) Nng lng

Mt Tri lin tc bc x nng lng ra xung quanh.

Hng s Mt Tri H l lng nng lng bc x ca Mt Tri truyn vung gc ti 1 n v din tch cch n 1 n v thin vn trong 1 n v thi gian. H bng 1360 W/m2 suy ra

PT = 3,9.1026

W

c) Hot ng:

Nm Mt Tri c nhiu vt en nht xut hin l nm Mt Tri hot ng. Nm t vt en nht l nm Mt Tri tnh.

Din ra theo chu k lin quan n s vt en trn MTri. Chu k hot ng ca MTri trung bnh l 11 nm.

Tm tt l thuyt vt l 12 n thi i hc luyn thi i hc

III. TRI T. 1. Cu to: Tri t c dng hnh cu dt. Rxch o = 6378 km, R2cc = 6357 km, Dtrung bnh = 520kg/m

3.

Tri t c li bn knh khong 3000 km c cu to ch yu l st, Niken.

Bao quanh li l lp trung gian, ngoi cng l l lp v dy khong 35 km, vt cht trong v c D = 3300 kg/m3.

2. Mt trng- v tinh ca Tt. Mt Trng cch Tri t 384000 km. RMtTrng = 1738 km, mMT =

7,35.1022

kg.

Mt Trng chuyn ng quanh Tri t vi chu k T = 27,32 ngy. Lun hng mt na nht nh ca Mt Trng v Tri t. Trn Mt Trng khng c kh quyn. B mt ph 1 lp vt cht xp. Trn b mt c cc dy ni cao. Nhit trong 1 ngy m chnh lch nhau rt ln. C nhiu nh hng n Tri t: gy ra hin tng thu triu.

IV. SAO THIN H. 1. nh ngha: Sao l khi kh nng sng, ging nh Mt Tri 2. c im: a s cc sao tn ti trong trng thi n nh, c kch thc

nhit .. khng i trong thi gian di. Mt Tri l mt trong s cc sao ny.

3. Cc loi sao: Sao bin quang: c sng thay i. C 2 loi:

+ Sao bin quang do che khut. + Sao bin quang do nn dn

Sao mi: c sng tng t ngt ln hng ngn, hng vn hay hng triu ln sau t t gim.

Punxa v sao ntron: bx nng lng di dng xung sng in t rt mnh.

L en l thin th cu to bi cc ntron, c kh nng ht mi vt th, k c nh sng.

Tinh vn: l nhng m my sng. 4. S tin ho: Sao c cu to t 1 m my kh v bi. m my va quay va co li, sau vi chc nghn nm, vt cht dn tp

trung gia , to thnh tinh vn. trung tm tinh vn, ngi sao nguyn thu c to thnh.

Sao tip tc co li v nng dn to thnh ngi sao sng t.

Trong thi gian tn ti ca sao, xy ra phn ng nhit hch, tiu hao dn Hir to thnh Heli v cc nguyn t khc (C, O, Fe..)

Khi nhin liu trong sao cn kit, sao bin thnh cc thin th khc.

V. THIN H 1. KN: Thin h l h thngsao gm nhiu loi sao v tinh

vn.

2. Cc loi thin h:

Thin h xon c l thin h c hnh dng dt nh ci a trn c nhng cnh tay xon c, cha nhiu kh.

Thin h elip l thin h c hnh elip, cha t kh v c khi lng tri ra trn 1 di rng.

Thin h khng nh hnh l thin h khng c hnh dng xc nh.

CH : Ton b cc sao trong mi thin h u quay xung quanh trung tm thin h.

VI. THIN H CA CHNG TA (NGN H) c im: Thin h ca chng ta l loi thin h xon c.

+ ng knh khong 100 nghn nm nh sng + Khi lng bng khong 150 t ln khi lng MTri. + L 1 h phng ging nh mt ci a, dy khong 330 nm nh sng, cha vi trm t ngi sao.

Phn trung tm Thin H c dng 1 hnh cu dt, gi l vng li trung tm. c to bi cc sao gi, kh v bi.

trung tm Thin H c ngun pht x hng ngoi v l ngun pht x sng v tuyn in.

Di ngn h: l hnh chiu ca Thin H trn vm tri nh mt di sng tri ra trn bu tri m.

Tm tt l thuyt vt l 12 n thi i hc luyn thi i hc

VII. THUYT BIG BANG. c im: V tr bt u dn n t mt thi im k d. Mun tnh tui ca v tr, phi lp lun i ngc thi gian n

im k d, lc tui v RVTr bng 0 (im zero Big Bag). Vt l hc hin i da vo vt l ht s cp c on c

nhng s kin xy ra bt u t thi im tp bng 10-35

s sau

V n ln bng> Thi im Plng. thi im Plng:

+ Kch thc v tr l 10-35 m,D bng 1091kg/cm3 nhit bng1032 K. bng> Tr s Plng. + V tr trn ngp bi cc ht c nng lng cao: electron, ntrin v quac.

S to thnh cc ht: Nucln c to ra sau V n 1s. Cc ht nhn nguyn t u tin xut hin sau 3 pht. 300 nghn nm sau xut hin cc nguyn t u tin. 3 triu nm sau xut hin cc sao v thin h. Ti t bng 14 t nm, v tr trng thi hin nay, nhit trung

bnh T bng 2,7 K.

The End

Chc cc em thnh cng trong cc k thi sp ti!

Tm tt l thuyt vt l 12 n thi i hc luyn thi

i hc