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#, doc theo mpt phdng nghi6ng.[r]
(1)so crAo DUC & EAO T4O QUANG TRI TRrroNG THPT crilrytN r,0 guf oON
of rnr cHeN Der ruynN ogrHr Hec srNH cror t Gp tz cAp riNn NAvr Hoc 2ots-zozo
Mdn thi: VAT LY
Thdi gian ldm bdi: I B0 philt
(Da thi g6m c6 02trang)
m Cflu I (3,0 di€m)
Ttr chdn cira mQt c6i n6m ttrOi luqng M, truydn cho m6t vQt nh6 khOi tuqng m vQn tO #, doc theo mpt phdng nghi6ng HQ s6 ma s6t
giira vft vd n6m ld p, goc gita m4t ph5ng nghi6ng clra ndm vd m6t ph[ng ngang li o, n6m c6 dQ cao h 86 qua ma s6t gifia n6m vd m{t phdng ngang Tim v4n t6c vo cgc d4i dO vflt kh6ng vuot qua dinh cira mdt ph6ng nghi6ng
Hufng din ch6m
h
Ciu II (4,0 di€m)
Edt mach diQn c6 so nhu hinh bon vdo mOt hiOu diQn th6 kh6ng aoi u. Hai ddn gi6ng vd diQn tro khong thay d6i Khi di6u chinh bi6n tro R6 ta th6y v6i hai gi|trl Rur : 1Q vi Rbz :4Q thi c6ng su6t ctra bitin tr6 c6 ctng m6t
gi|tri P:25W Edn D1 c6 c6ng su6t pr :125W.
a) Tinh hiQu diQn th.5 U, diQn tro R vd diQn trd m6i ddn?
b) Tim gi|tri Rb de c6ng su6t tiOu thp tr6n bi6n tr6 d4t gi6tri cpc d4i Tinh gi6 tri cgc d4i d6
Huttug d6n ch6m
U
Cflu NQi dung Di6m
D6 vat khdng vugt qua ducv c <tinh thi vomax vat dung lai t4i rlinh n€m tric ld ctng
vfln t6c v vdi n6m
0,5
Ddng lugng theo phuong ngang dugc b6o todn:
myom*cosd =(m+ M)v mcosa
1' v=
m+M vorru,
1
Ap dpng itlnh lu6t b6o todn nlng lugng:
I , 7, .-\ ) h
* *uo,n ' = *(* + M)v2 + mgh + pmg cos
aT-z z' stna
1,0
2(m+ M gh l+ pcota
1V^ utnax
M +msin2 a
0
(2)Ciu NQi dung Ei6m
a) Ap dung ngu6n tuong ducrng cho hai nhSnh (U, R) vd Dz
RR^
5
R+R, R,,
U ,R+R,
0,5
/z\2
I ln,
In,+r] n
C6ng su6t bi€ntr6: P =
<> Rr'+(,,
y2
Ro+12 =0 P
0,5
Tt he thfc Vi-61, ta c6:
RorRo, = 12
R^ + Ru, =t-r, ={
, =z(a)
€:rs(v)
0,5
Mdt khsc ,, =t
0,5
.I-lU 25(rr)
/3(o) (o)
R=10
RD
1,0
b) 1,0
a) Truong hqp d: l,5cm, tim b6n kinh qu! dpo vd thdi gian chuy6n dQng cta electron tir trucrng
b) Tim d nh6 ntr6t AO thdi gian electron chuy6n d6ng tu trucrng la lcrn ntr6t tim thcyi
gian d6
Hu6,ng din chdm
I
V
"4
0
-+
B
@
d
Trang2/5
Ir I I
t_-_r_ I
l.-ft R,., I
1t tr u "lI
l';- n t
Tri phuong trinh c6ng su6t bi6n trd tr6n, 6p dpng bdt dtngthric C6si ta c6: r2
P*^=L:28,725(W) khi & =r:2(A) CAu III (4,0 di€m) "
M6t electron dang chuy6n dQng voi vfn 6c vo: 8.107m/s thi bay vdo
mQt virng c6 tir trudng d0u bO aay d, t o lu6n vu6ng goc vcri cim ring tu i
(3)V,
Cflu Ndi dung Di6m
a) B6n kinh qu! tl4o R dugc x6c cllnh
2
lo,luon=ry
e.R -
#=t,S(cm)
1
d : R = qu! clpo tt'trudng ld mOt cung trdn c6 g6c P: nl3 0,5
Thdi gian chuy6n tlQng cria electron tt trudng ld:
t = 0R =1,875r.10-10 ^r 5,89.10-'o (r)
yo
1,0
b) D6 d,,,1, thi qu! dpo ti6p xirc v6i bd b6n Qu! clpo tu trucrng ld mQt cung trdn
c6g6c y:4n13.
0,5
* d*io= R + R sin a = 2,25(cm) t,,* =f R =2,5n.10-to x7,85.10-'o (s)
yo
1)0
C0u IV (3,0 diAm)
MQt qui cAu sut5t c6 chi6t su6t n d{t trong kh6ng khi MOt tia s6ng dugc chi6u vdo qui
cAu du6i g6c t6i i (i < 905.
a) Hdy chimg minh tia sSng lu6n 16 kh6i qui cAu sau hai lAn khric x4
b) Tim bi6u thrlc g6c lQch cira tia sdng sau khi truyOn qua qui cAu Ap dUng s6 i : 600,
t; n=1J.
Hutitrg dfin chdm
Cdu NQi dung Di6m
a) Trong mQt mit phing t6ib6tky thi6t diQn cta mflt phlng t6'i vd qu6 cAu h mQt hinh trdn d lan khirc xa thri nh6t, ta c6:
J
sinl 1
Slnf=-<-=Sln
nn lsn I I
+ r lirn
Vfly tia s6ng d6n mflt cAu lAn thir hai n6 sE khric
xp m6i trucvng b6n ngodi
2,0 (h.vE
0,5)
b) Tri hinh v6, ta c6:
sin I
, - arcsln
-n
o=2(i-r)=2
(4)D=2
dung
600-arcsmlS- sin 600 600
CiuV (6,0 didm)
a) MOt ld xo c6 dQ ctmg 20N/m, dAu tr6n duoc treo vdo m6t diom c6 dinh, dAu du6i g6n v{t
nh6 A cO khOi luqng 1009 Khi vQt A dang nim y6n o vi trf c6n bang thi mQt vQt e kh6ituqng 2009 chuyOn dQng tir du6i l6n v6i v{n t6c 37,5J6 cm/s va cham mdm vdo vQt A Tim bi6n dQ
dao dQng cta hQ v{t sau d6
b) Hai l6c dcrn gi6ng hQt md c6c vQt nh6 c6 khdi lugng m: 100g vd mang diQn tich ducrng q nhu nhau, ducvc treo o mQt noi tr6n mi4t ddt Trong m6i vung kh6ng gian chuam6i l6c c6 mQt diQn trudrng dAu Hai diQn trucrng ndy c6 ctng cu&ng dO t: 10'V; rrhung c6c dulng
sric nguoc hu&ng Bitit phucrng cria c6c dudng sric hgp vdi phucrng thang dring mQt g6c o: 9.oo,tiu ti5c trgng trudng B: 10m/s2 vd chu ky daotQng di6u hda cria c6c l6c gap rrrrl 1,236 lan llm q
c) Hai ch6t di6m dao dQng di6u hda doc theo ducmg thing o1O2 ctng tAn s6 cung bi6n dQ
'q = +Ji km)nhmglQch pha nhau2nl3.gi6t or vd oz chinh ld vi tri c6n bang cira hai ch6t dicm vd OrOz: 15cm X6c dinh khoang c6ch cr,rc dpi vd cuc ti6u giffa hai ch6t diom
Hurfng d6n chdm
Cdu NQi dung
Di6m
Theo dinh luat beo todn d6ng lugng: ffiavn =(*o*mu)v
<+ v - *!I:v, =25J6(cm I s)
mA+ mB
0,5
EQ l6n li dQ ctra hQ vft ngay sau va cham ld:
lr'l = do,- Lto =@*P -ry =rckm)
0,5 a)
Bi6n d0 dao tl6ng cria h0 v6t:
A_ =I2,5(cm)
k
x'2 +(mn+m,),'
1,0
b) Lpc cliQn t5c dpng l6n diQn tfch F: qE
Trgng luc bi6u kiiSn t6c dpng l6n mdi l6c ld:
P2 + F2 -2pF cosa = P2+F2_PF
P2 + F2 +2PFcosa = P2+F2+PF
P1 =
Pr=
0,5
(5)-.HET Md theo adru, L= E = E =L236
r, !g, \p,
05
r = 0,5(N) F =2(N)
g = 0,5.10-t (C) q =2.10-' (c)
1,0
c) Gi& sir phuong trinh dao dQng cria hai ch6t di6m ld:
xt = 4'Ecos(att)(cm);xz =
'l-3cos(att +2t lz)(cm) Khoang c6ch gifia hai chAt di6m d thoi di6m t ld:
4 =loro, * xz -r, I = |t5 +t2cos(att - r I 6)l(cm)
1,0
d =27cm d*r, =3cm
1,0