bien thien tuan hoan theo thai gian voi chu ky bang chu ky dao dong ciia vatA. bang dong nang ciia vat khi vat qua vi tri can bang.[r]
(1)Cau 37 : Mot song truyen tren mat nuoc co buac song 0,4 m Hai diem gan nhat tren mot phuong truyen 7t
song, dao dong lech pha goc —, each mot khoang
A 0,15 m B 0,2 m C 0,4 m D 0,1m
Cau 38: f Mot song ngang co phuong trinh song la u = cos27t
v
o,i
(cm) x tinh bang m, t tinh bang giay Buac song cua song co gia tri la
A m B 0,8 m C 0,5 m D m
Cau 39 < t ^
(mm) x tinh bang cm, t tinh Mot song ngang co phuong trinh song la u = 5 COSTI
bang giay Do lech cua mot phan tir vat chit M moi trudng truyen song each nguon mot khoang x = 0,2 m a thai diem t = s la
A 2,5 cm B mm C cm D
Cau 40 : Mot song am co tan s6 200 Hz lan truyen mot moi trudng vai van t6c 1500 m/s Buac song cua song moi truong la
A m B 75 m C 7,5 m D 30,5 m B Theo chirong trinh Nang cao (8 cau, tu* cau 41 den cau 48)
Cau 41: Mot vat ran quay deu quanh mot true co dinh vai toe goc 360 vong/phut Lay n1 = Biet dong nang quay cua vat bang 36 J Momen quan tinh cua vat ran doi vai true quay bang
A 0,05 kg.m2 B 0,1 kg.m2 C 0,01 kg.m2 D 0,5 kg.m2
Cau 42 : Mot banh xe quay nhanh dan deu s, t6c goc tang tir 120 vong/phut den 360 vong/phut Toe dp goc tai mot diem tren vanh banh xe sau tang toe dupe s la
A On rad/s B 12TT rad/s C 14TI rad/s ' D Sn rad/s
Cau 43 : Mot banh xe quay nhanh dan deu tir trang thai dung yen, sau s no dat toe dp goc 10 rad/s Gia toe goc cua banh xe la
A 2,5 rad/s2 B rad/s2 C 12,5 rad/s2 ^ D 10 rad/s2
Cau 44 : Mot lie vat ly dao dong vai bien dp nho, co momen quan tinh doi vai true quay la I, khoi lupng m, khoang each tir true quay den tarn cua lac la d Bieu thuc xac dinh t i n so dao dong ciia lac la
A.
f=2*Nl B / - L L c / - f JJU D / = f J ^
V / \mgd 27t\mgd 2n\ I Cau 45 : Phuong trinh dong lire hoc ciia vat ran quay quanh mot true co dinh la1 ,
A W = - I.co2 B M = F.d C M = I.y D L = I.eo
2
Cau 46 : Mot dTa dac quay quanh true vuong goc vai dTa DTa chiu tac dung mot momen lye khong doi Nm Sau s k l tir liic bit dau quay, toe dp goc cua dTa la 10 rad/s Momen quan tinh ciia dTa d6i vai true quaj la
A 2kgm2 B 5kgm2 [ C kgm2 D 0,5 kgm2
Cau 47 : Khi mot vat ran dang quay cham dan deu quanh mot true co dinh xuyen qua vat thi A gia t6c goc luon co gia tri am B toe dp goc luon co gia tri am
C tich t6c dp goc va gia t6c goc la so am D tich t6c dp goc va gia toe goc la so duong Cau 48 : Mot van dong vien trupt bang nghe thuat dang bieu dien quay tit quanh true thang dung tir than dei
dau N6u liic dang quay, hai tay dang dang bong khep lai thi chuyen dong quay ciia van dong vien cham lai neu khong _ t_ u i_ * u' - U A ~ I •
A ' & B nhanh horn C vannhucu D cham lai
lay da
H E T
(2)SO GIAO DUC VA DAO TAO THANH PHO CAN THO
DE CHINH THlfC
(De thi gom co trang)
Ho va ten thi sinh So bao danh :
DE K I E M TRA CHAT Ll/ONG GlCA HOC K Y I NAM HOC 2010-2011
MON: VAT L Y LOfP 12 THPT
Thai gian lam bai: 60 phut, khong ke thai gian giao de
M a de: 852
PHAN CHUNG CHO T A T CA THI SINH (32 cau, tir cau den cau 32) C a u l :
A C Cau : A C Cau : A B C D Cau 4: A B C D Cau :
A Cau 6:
A Cau 7:
A Cau 8: A B C D Cau 9: A Cau 10:
A Cau 11:
van khong doi tang len lan
co nang ciia dao dong khong doi bien khong doi
Con lac don dao dong vai bien dp nho dupe xem la dao dong dieu hoa Khi tang khoi lupng cua vat len lan thi chu ky dao dong ciia vat
giam di 4l lan. w
-tang len lan D Dao dong tat dan cua lac don co dac diem la
Co nang cua dao dong giam dan B dong nang cua lac a vj tri can bang luon D
khong doi
Khi noi ve dao dong tat dan, phat bieu nao sau day co npi dung sai ?
Luc can ciia moi truong hoac lire ma sat cang nho thi dao dong tat dan cang cham Dao dong tat dan co bien dp giam dan lure ma sat hoac lire can ciia moi truong Tan so dao dong cang Ion thi qua trinh dao dong cang keo dai
Nang lupng ciia dao dong tat dan giam dan theo thai gian
Doi vdi mot vat dao dong dieu hoa, phat bieu nao sau day co npi dung sai ? Khi vat qua vj tri can bang thi dong nang bang ca nang toan phan
Khi vat di tir vj tri can bang den vi tri bien, the nang cua vat giam dan Khi vat a vi tri bien thi dong nang triet tieu
Khi vat di tir vi tri bien ve vi tri can bang, dong nang cua vat tang dan
Mot lac don co chilu dai day treo la m Keo lac lech khoi vi tri can bang mot goc 60° roi buong tay tha cho dao dong Bo qua ma sat Lay g = 10 m/s2 Van t6c cua vat no qua vi tri can bang
co dp Ion
3,16 m/s B 1,58 m/s C 1,63 m/s D 10 m/s
Mot dao dong dieu hoa co phuong trinh x = Acos(cot + q>) Dong nang va the nang cua vat cung bien thien dieu hoa vai tan so
4(0 B.
—
C co D 2co2
Vat co kh6i lupng m = 100 g thuc hien dao dong tong hop cua hai dao dong dieu hoa ciing phuong,
71
cimg tan so vai cac phuong trinh la xi = cos (lOt + 7t) (cm) va X2 = 10 cos (lOt - —) (cm) Gia tri cue dai ciia lire tong hop tic dung len vat la
0,5V3N B V N C N D 5V3 N Bien dp ciia dao dong cuang birc khong phu thupc
tin so ciia ngoai lire tuan hoan tac dung len vat bien dp ciia ngoai lire tuan hoan tac dung len vat he so lire can tac dung len vat dao dong
pha ban dau ciia ngoai lire tuan hoan tic dung len vat
Tai ciing mot vi tri dia ly, hai lac don co chu ky dao dong lan luot la Tj - s va T2 = 1,5 s Chu ky dao dong cua lac thu ba co chieu dai bang hieu chieu dai cua hai lac noi tren la
2,25 s B 1,35 s C 2,05 s D 1,32 s
Mot lac 16 xo co chieu dai cure dai va cue tieu ciia 16 xo qua trinh dao dong dieu hoa lan luot la 28 cm va 22 cm Bien dp dao dong ciia lac la
12 cm B cm C cm D 24 cm
Qua nang ciia lac 16 xo dao dong dieu hoa tren quy dao dai 10 cm, chu ky T = s Chpn goc thai gian vat qua vi tri can bang theo chieu am Phuong trinh dao dong ciia vat la
(3)71 71
A x = 10cos(7rt ) (cm) B x = 5cos(27rt + —) (cm)
C x = 5cos(27rt - —) (cm) D x = Ocos(7rt + —) (cm)
Cau 12 : Hien tugng cpng huong xay
A tan so cua lire cuong buc bang t i n so rieng cua he B tan so ciia lire cuong buc nho hern t i n so rieng ciia he C tan so ciia luc cuong buc Ion hon tan so rieng ciia he D tan so ciia dao dong bang tan so rieng cua he
Cau 13 : Mot lac 16 xo gom vat nang co kh6i lupng m va 16 xo co cung k thirc hien dao dong dieu hoa Khi mac them vao vat m mot vat khac co kh6i luong Ion gap lan vat m thi chu ky dao dong ciia lac giam di lan B tang len lan C ting len lan D giam di lan
Mot vat thirc hien dao dong tong hop cua hai dao dong dieu hoa cung phuong, cung tan so vai cac phuong trinh : xj=2 sin ©t (cm), x2 = 2-\/3 cos&tf (cm) Bien va pha ban dau ciia dao dong tong hop la
71 7t 71 . 7 1
5cm,-— B 4cm,— C 4cm,-— D Dcm,—
3 6 Mot vat gan vao 16 xo co ciing k = 20 N/m dao dong voi bien A = cm Khi vat nang each vi tri
bien cm, no co dong nang la
0,041J B 0,009 J C 0,0016 J D, 0,025 J
Mot vat thuc hien dao dong dieu hoa theo phuong trinh : x = 6cos47tt (cm) Van t6c cua vat tai thai diem t = 7,5 s la
0 B 75,4 cm/s C -75,4 cm/s D cm/s
71
Hai dao dong dieu hoa cung phuong, cung tan so co cac phuong trinh la xi = A cos(cot + —) va
2.71
x2 = A cos(cot - —— ) la cac dao dong
71 7t
cung pha B lech pha — C ngugc pha D lech pha —
Mot vat dao dong d\hx hoa, phut thuc hien dupe 30 dao dong toan phan Quang duong ma vat di duoc s (ke tu vi tri bien) la 64 cm Bien dp dao dong ciia vat la
4 cm B cm C cm D cm
Mot lac don co chieu dai day treo la £ dao dong dieu hoa voi bien dp goc a0 Chpn goc the nang a
vi tri can bang Bo qua ma sat va lire can ciia moi truong Co nang ciia lac dupe xac dinh bai bieu thuc :
A W= mg(£-cosa0) B W = ^mg£ (\-cos a 0)
C W= mg£(l-cosa0) D W = g£(cosa-cosaj
Cau 20 : Mot lac don treo vat co kh6i lupng m = 200 g thi dao dong dieu hoa voi chu ky T = s Thay vat m bang vat co khoi lupng m' = 400 g thi lac dao dong dieu hoa vai chu ky
A 2s B V s C I s D 0,5s
Cau 21: Mot vat thuc hien dao dong dieu hoa Thai gian ngan nhat vat di tu vi tri can bang den vi tri bien la 0,2 s Chu ky dao dong ciia vat la
A 0,8 s B 0,4 s C 0,1s D 1,6 s
Cau 22 : Mot he dao dong chiu tac dung cua mot ngoai lire tuan hoan Fn = F0sin lOrrt thi xay hien tupng
cpng huong Tan so dao dong rieng ciia he la
A 5TI Hz B 10 Hz C Hz D I O T C H Z
Cau 23 : D6i vai lac 16 xo dao dong dieu hoa theo phuong nam ngang, ket luan nao sau day co npi dung dung ?
A Luc keo ve la lire B Luc keo ve la lire dan hoi
C Luc keo ve la hop lire cua luc dan h6i va D Luc keo v£ la hop lire ciia lire dan hoi va lire ma luc sat Cau 24 : Mot vat dao dong diSu hoa tren quy dao dai 20 cm 6' vj tri can bang, vat co van t6c 207t cm/s Chu ky
dao dong ciia vat la
(4)A s B 0,5 s C 0,1 s D. s
Cau 25 : Trong sir tang hop hai dao dong dieu hoa cung phuong, cung tan s6, khac bien va pha ban dau, bien dao dong tong hop
A Nho nhat nSu hai dao dong cung pha B 1cm nhit nlu hai dao dong nguoc pha
C Thoamanhethuc : U -A2\>A>Al+A2 D' & v ao d? ^ ch Ph a c"a h a i d ao ^ 11 1 phan
Cau 26 : Mot vat thuc hien dao dong dieu hoa voi chu ky 0,2 s Khi vat qua vi tri co ly cm, vat co van t6c 60TT cm/s Bien dao dong cua vat bang
A 12 cm B cm C 15 cm D 10 cm
Cau 27 : Mot lie don dao dong dieu hoa, thai gian t no thuc hien duoc 21 dao dong Tang chieu dai lie them 4,1 cm thi cung thai gian t no thuc hien duoc 20 dao dong Chieu dai ban dau ciia lac la
A 32 cm B 40 cm C 36 cm D 25 cm
Cau 28 : Mot lie go giay (coi nhu mot lie dan) co chu ky T = s Tai nai co gia t6c truong g = 9,8 m/s2 , chieu dai day treo cua lac la
A 96,6 m B 0,04 m C 0,993 m D 3,12 m
Cau 29 : Mot lie don thuc hien dao dong dieu hoa voi bien nho Chu ky dao dong cua lac khong doi
A thay doi khoi luong cua lac B thay doi chieu dai ciia lac C thay d6i nhiet noi dat lie D thay doi cao nai dat lac
Cau 30 : Mot he dao dong g6m vat co khoi luong 0,4 kg treo vao mot 16 xo co ciing 80 N/m thuc hien dao dong dieu hoa theo phuong thing dung vai bien 0,1 m Gia toe cua vat a vi tri bien co Ion la
A m/s2 ' B Om/s2 C 10 m/s2 D 20 m/s2
Cau 31: Mot lie don co kh6i luong vat nang m = 400 g, chieu dai day treo = 50 cm Keo lie lech khoi vi tri can bang mot goc 60° roi buong tay tha cho dao dong Lay g = 10 m/s2 Luc cang day vat
qua vi tri cao nhat la
A 20 N ' B I N C 100 N D N Cau 32 : Co nang cua mot vat dao dong dieu hoa
A bien thien tuan hoan theo thai gian voi chu ky bang chu ky dao dong ciia vat B bang dong nang ciia vat vat qua vi tri can bang
C tang gap doi bien dao dong ciia vat tang gap doi
D bien thien tuan hoan theo thai gian vai chu ky bang nua chu ky dao dong cua vat PHAN RIENG
Thi sinh chi chon mot phan rieng thich hop de lam bai; neu lam ca hai phan rieng thi ca hai phan rieng deu khong duoc cham
A Theo chuong trinh Chuan (8 cau, tir cau 33 den cau 40)
Cau 33 : Khao sat hien tupng song dimg xay tren day dan h6i A B , dau A n6i voi nguon dao dong, dau B duoc gift co dinh Tai dau B, song tai va song phan xa
A nguoc pha vai B cung pha vai
C Co pha vuong goc , , m D lech pha mot goc —
Cau 34 : Mot nguai quan sat tren mat h6 thay khoang each giua hai ngon song lien tiep bang 1,2 m va co ngon song di qua truac mat thai gian s Van toe truyen song tren mat nuac la
A 0,6 m/s B 1,2 m/s C 0,8 m/s D 2,4 m/s
Cau 35 : Mot sai day AB co chieu dai 80 cm, dau B duoc gift c6 dinh, dau A dao dong dieu hoa vai t i n so 50 Hz Tren day co song dimg vai bung song, coi A va B la cac nut song Van t6c truyen song tren day la
A m/s B 20 m/s C 40 m/s D 10 m/s
Cau 36 : Mot nguon phat song co phuong trinh dao dong : u = 3cos207rt (cm) Van t6c truyen song la m/s Phuong trinh dao dong ciia mot phan tu vat chat moi truong truyen song each nguon mot khoang 20 cm la
A u = 3cos(207it - —) (cm) B u = 3cos(207tt + —) (cm)
2 C u = 3cos(207rt - 7t) (cm) D u = 3cos207rt (cm)