CNG N THI HC K I - VT L 10 NNG CAO NM HC: 2011-2012
A) L THUYT 1/ Th no l s ri t do? Nu cc c im ca chuyn ng ri t do
ca mt vt.2/ Th no l chuyn ng trn u? nh ngha: chu k v tn s trong
chuyn ng trn u. Vit
cc cng thc lin h gia chu k, tn s, tc di v tc gc trong chuyn ng
trn u. 3/ Trnh by phng, chiu v ln ca vect gia tc hng tm trong chuyn
ng trn u 4/ Th no l tng hp lc? Th no l phn tch lc? Nu quy tc tng hp
lc. 5/ Pht biu v nu ngha ca nh lut I Niu-tn.6/ Pht biu v vit biu
thc ca nh lut II Niu-tn. Nu iu kin cn bng ca mt cht im.
7/ Pht biu v vit biu thc ca nh lut III Niu-tn.8/ Pht biu v vit
biu thc ca nh lut vn vt hp dn. 9/ Nu khi nim v lc n hi? Trnh by
phng, chiu v ln lc n hi ca l xo. Pht
biu nh lut Hc i vi l xo.10/ Khi no xut hin lc ma st ngh, lc ma
st trt, lc ma st ln? Trnh by phng, chiu v
ln ca lc ma st ngh, lc ma st trt, lc ma st ln.11/ nh ngha v vit
biu thc (nu c): lc qun tnh, lc hng tm, lc qun tnh li tm.
B) BI TP1/ Chuyn ng thng u, thng bin i u, ri t do. 2/ Chuyn ng
trn u.
3/ Tng hp v phn tch lc.4/ Ba nh lut Niutn: gii thch hin tng v bi
tp nh lng.
5/ Lc hp dn gia hai vt.6/ Chuyn ng ca vt nm xin, nm ngang, nm
thng ng. 7/ Lc n hi, bin dng ca l xo.
C) BI TP THAM KHO 1/ T vch ni, mt ngi bung ri mt hn xung vc su.
T lc bung n khi hn chm y vc ht 6,5 giy. Tnh : a) Thi gian ri s: a)
6 s b) 180m c) 25m b) khong cch t vch ni n y vc . c) qung ng vt ri
trong giy th 3 . Cho g = 10m/s2, vn tc truyn m l 360m/s.
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2/ Mt v tinh nhn to chuyn ng trn u quanh tri t mi vng ht 90 pht.
V tinh bay
cao 320km so vi mt t. Tnh tc gc, tc di v gia tc hng tm ca v
tinh? Bit bn knh tri t l 6380km. s: = 1,16.103 (rad/s) ; v = 7772
m/s ; aht = 9016 m/s23/ Xc nh ln v hng ca hp lc ca 3 lc trn hnhu u
r F1 ur u F2
v. Bit F1 = F2 = 10 N ; F3 = 20 N ; = = 600 .ur u s: hp lc c ln
26,5N ; hp vi F3 mt gc 410
ur u F3
4/ Tri t c khi lng m1 = 5,96.1024 kg, bn knh R1 = 6400 km. Mt
trng c khi lng
m2 = 7,3.1022 kg, bn knh R2 = 1740 km. Cho bit tri t v mt trng
cch nhau 384000km. a) Tnh lc hp dn gia tri t v mt trng b) So snh
gia tc ri t do trn b mt hai thin th g 1 c) Gi s t b mt mi thin th
trn, ta nm mt vt ln theo phng thng ng vi cng vn tc ban u v0. Hy so
snh cao hai vt t ti. s: a) F 1,97.1020 N2 2 b) g 0,166 c) h = 6 1
1
g2
g
h
5/ Gia tc ri t do ca mt vt cch mt t khong h l g = 4,9m/s2. Cho
gia tc ri t do trn
mt t l g0 = 9,8 m/s2 , bn knh tri t l R = 6400 km. Tm h? s :
2651km6/ Mt vt c khi lng 1,25 kg c nm ln t mt t theo phng xin hp vi
mt nm
ngang mt gc 600. Cho bit vn tc ban u l v0 = 20m/s. Ly g =
10m/s2. B qua mi sc cn khng kh. a) Vit phng trnh chuyn ng ca vt b)
Vit phng trnh qu o ca vt c) Tnh tm bay cao v tm bay xa ca vt. Tnh
vn tc ca vt v tr cao nht. d) cao no so vi mt t vn tc ca vt hp vi
phng ngang mt gc 300 e) Tnh thi gian v vn tc ca vt ngay ti thi im
vt bt u chm t. Tm gc to bi vecto vn tc lc ny so vi phng ngang. s:
a) x = 10t ; y =10 3.t 5t 2 b) y = d) h 13,3mx2 + x 3 (m) c) H=15m
; L = 20 3( m) ; 5 3 (m/s) 20
e) 2 3( s ) ; 20m/s ; 600
7/ Mt vt c nm ngang t cao h = 4,9m so vi mt t vi vn tc ban u l
5m/s. Cho g =
9,8m/s2. B qua sc cn khng kh. a) Vit phng trnh qu o ca vt . V qu
o chuyn ng b) Tnh thi gian chuyn ng ca vt t lc nm cho n khi bt u
chm t. c) Tnh tm bay xa ca vtTrang - 2 -
d) Cng lc nm vt ny ngi ta cng ng thi nm mt vt khc ln cao theo
phng thng ng vi vn tc ban u l 12 m/s. Bit ban u hai vt cch nhau
0,5m Hai vt c ny c gp nhau khng ? Nu c tm thi gian gp nhau ca chng?
s: a) Chn h ta - cc Oxy tha mn : Ox theo chiu v0 ; Oy hng xung : y
= - 0,196x2 + 4,9 b) 1s c) L = 5m d) thi gian gp nhau : 0,41 s 8/
Tnh cng ca h l xo c ghp vi nhau nh hai hnh v. Cho bit k1 = 100N/m ;
k2 = 200 N/m1 2 s: hnh 1 : k = k + k = 3 (N/m) ; hnh 2: k = k1 + k2
= 300 (N/m) 1 2
k1 k2
k1
k2
k .k
200
9/ Mt l xo c khi lng khng ng k, khi treo vt m = 100g th
Hnh 1
Hnh 2
dn
ra 5cm. Cho g = 10m/s2. a) Tm cng ca l xo b) Khi treo vt m' , l
xo dn 3cm. Tm m' ? s: a) 20N/m b) 60g 10/ Vt khi lng 100g gn vo u l
xo di 20cm, cng 20N/m quay trn u trong mt phng nm ngang vi tn s 60
vng / pht. Tnh dn ca l xo. s : 5cm11/ Mt l xo c chiu di t nhin l
20cm , vt m = 500g c b tr nh hnh v. Cho
cng l xo l k = 100N/m. Hy tinh chiu di ca l xo khi vt ng yn. Cho
g = 10m/s2 . ( s: 15cm )12/ Mt l xo c khi lng khng ng k . Treo vt c
khi lng m1 = 100g th l xo c chiu di
l l1 = 31cm. Treo thm mt vt c khi lng m2 = 200g vo th l xo c
chiu di l l2 = 33cm. Tnh cng v chiu di t nhin ca l xo. Cho g =
10m/s2. (s: 30cm; 100N/m)13/ Mt vt c khi lng m = 5kg nm trn mt bn
nm ngang, h s ma st trt gia vt v mt r sn l 0,2. Tc dng vo vt lc F
song song vi mt bn. Ly g = 10m/s2. Tm:
a) Gi tr ca lc F vt khng chuyn ng b) Qung ng vt i c khi tc dng
lc F1 = 20N trong 2s ri sau thi tc dng lc. (s: a) F 10 N b) 8m)r
14/ Mt vt khi lng 2kg c ko bi mt lc F hng ln hp vi phng ngang mt gc
= r 300. lc F c ln 8N . bit sau khi bt u chuyn ng 2s t trng thi ng
yn vt i c
qung ng 4m. Ly g = 10m/s2. a) tnh h s ma st gia vt v mt ngang.
b) cho vt c th chuyn ng thng u th F c ln l bao nhiu? (s: a) = 0,18
; b) F ' = 3,77N) 15/ Mt vt ang chuyn ng trn ng ngang vi vn tc
20m/s th trt ln mt ci dc di 100m, cao 10mr
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a) Tm gia tc ca vt khi ln dc. Vt c ln ht dc khng? nu c, tm vn tc
ca vt nh dc v thi gian ln dc. b) Nu trc khi trt ln dc vn tc ca vt
ch l 15m/s th on ln dc ca vt l bao nhiu? Tnh vn tc ca vt khi tr li
chn dc v thi gian k t khi vt trt ln cho n khi n tr li chn dc. Cho
bit h s ma st gia vt v dc l 0,1. ly g = 10m/s2 . (s: a) a= -1,995
m/s2 ; vt ln ht dc ; 1m/s; 9,52s b) 0,75m/s ; 157,5s)
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