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c_Ö g c‡Îi As‡Ki mgvavb ‡gv: kvn Rvgvj
mnKvix Aa¨vcK (c`v_©weÁvb wefvM )
First Paper Mathematics Solution we G Gd kvnxb K‡jR ‡ZRMuvI, XvKv
3| MwZwe`¨v (Dynamics) ‡dvb: +8801670856105, +88029125630, +88029115369

e-mail: [email protected]

1| GKwU e›`‡y Ki ¸wj †Kvb †`Iqv‡ji g‡a¨ 0.04m cÖ‡ek Kivi 3| 20ms-1 †e‡M MwZkxj GKwU e¯‘i †eM cwÖ Z †m‡K‡Û 3ms-1 nv‡i
ci A‡a©K †eM nvivq | MywjwU †`Iqv‡ji
g‡a¨ Avi KZUKz z cÖ‡ek Ki‡e? n«vm cvq| †_‡g hvIqvi Av‡M e¯‘wU KZ `i~ Z¡ AwZµg Ki‡e?

Avgiv Rvwb, v2 = u2 – 2as GLv‡b,
ev, 0 = 202 – 2(3)s Avw`‡eM, u = 20 ms-1

g‡b Kwi, ev, 6s = 400 g›`b, a = 3 ms-2

jÿ¨¯‡’ j c‡Ö e‡ki gyn~‡Z© ¸wji Avw`‡eM = u ev, s  400 ‡kl‡eM, v = 0
Ges ¸wjwU AviI x wgUvi `i~ Z¡ c‡Ö ek Ki‡e| 6 _vgvi Av‡M e¯‘wU KZ…K

0.04 m cÖ‡ek Kivi ci †eM n‡e = u s  66.7 m (Ans.) AwZµvšÍ `i~ Z,¡ s = ?
2
4| Dc‡ii w`‡K wbwÿß GKwU ej †Uwj‡dvb Zvi‡K 0.70ms-1 `ªæwZ‡Z
Ges †kl †eM n‡e 0 (k~b¨)|
Avgiv Rvwb, cÖ_g As‡ki Rb¨ AvNvr K‡i| †Qvovi ¯’vb †_‡K ZviwUi D”PZv 5.1m n‡j ejwUi Avw`

 u 2  u2  2a(0.04) `ªæwZ KZ wQj?

2 Avgiv Rvwb,
v2  u2  2gh GLv‡b,
 0.08a  u 2  u 2  (0.7)2  u 2  2  9.8 5.1
4  u 2  (0.7)2  2 9.8 5.1 D”PZv, h =5.1m
 u 2  0.49  99.96 g = 9.8 ms-2
 a  3u 2  3u 2 ..... .......... (1) ‡kl †eM, v =0.70ms-1
4  0.08 0.32 Avw` `ªæwZ, u =?

wØZxq As‡ki Rb¨,

0   u 2  2ax  u2  100.45
2
u  100.45 10.02 ms-1 (Ans.)

ev, 0   u 2 2 3u 2 x 5| GKwU †Ubª 3ms-2 mgZi¡ ‡b Pj‡Q Ges Avw`‡eM 10m/s †UªbwU hLb

 2  0.32 60m c_ AwZµg Ki‡e ZLb Gi †eM KZ n‡e|

ev, 6u 2x  u 2 Avgiv Rvwb, GLv‡b,
0.32 4
v2  u2  2as Zi¡ Y, a = 3ms-2
 x  0.32  0.0133 m (Ans.)  v2  102  2  3  60 Avw`‡eM, u = 10 ms-1
64  v2  100  360 miY, s = 60m
 v2  460
‡kl‡eM, v = ?

2| 50 wgUvi DPyu †_‡K GKwU e¯‘ fw~ g‡Z cwZZ nq|  v  460  21.447  21.45ms1 (Ans)
(K) fywg‡Z †cŠQu ‡Z Gi KZ mgq jvM‡e?
(L) fwy g‡Z †cŠQu evi ce~ © gny ‡~ Z© Gi †eM KZ n‡e? 6| GKwU e¯‡‘ K 98 ms-1 †e‡M Lvov Dc‡ii w`‡K wb‡ÿc Kiv n‡j

(K) h  ut  1 gt 2 GLv‡b, †`LvI †h, 3 Sec I 17 Sec mg‡q e¯i‘ †eMØq mgvb wKš‘ w`K
2 D”PZv, h =50m
Avw`‡eM, u = 0 wecixZ gLy x| GLv‡b,
 50  0  1 9.8  t 2 g = 9.8 ms-2 Avgiv Rvwb, Avw`‡eM, u = 98 ms-1
2 (K) mgq, t = KZ? 3 †mt c‡i †eM
(L) ‡kl †eM, v = KZ ? mgq, t1 = 3S
 50  4.9t 2 v1 = u gt1 mgq, t2 = 17S
 t 2  50 ev, v1 = 989.8×3 †kl‡eM, v1 =?

4.9 ev, v1 = 9829.4 †kl‡eM, v2 =?

 t  50 v1 = 68.6ms-1
4.9
Avevi, 17 †mt c‡i †eM
t = 3.19 s (Ans.)
Avevi, v2 = u gt2
(L) v = u + gt ev, v2 = 98 9.8×17

⇒ v = 0 + 9.8 × 3.19 ev, v2 = 98 166.6

v = 31.26 ms-1 (Ans.) v2 = 68.6 ms-1
3 †mt I 17 †mt c‡i †eR Øq mgvb I wecixZ (cÖgvwYZ)


3| MwZwe`¨v (Dynamics) 2

7| s  1 t3  3t mÎ~ vbmy v‡i GKwU e¯‘ mij †iLvq Pj‡Q|  t 2  2  1.414s
3 ‡k‡li 1m `i~ Z¡ AwZµg Ki‡Z mgq

2 †m‡KÛ ci Gi †eM KZ n‡e? jv‡M, t  t2  t1  (1.414  1) s  0.414s (Ans.)

Avgiv Rvwb,

v  ds GLv‡b, 10| GKwU ‡Uªb w¯’i Ae¯v’ b n‡Z 10ms-2 Z¡i‡Y Pj‡Z Avi¤¢ Kij| GKB
dt mgq, t = 2 Sec mgq GKwU Mvwo 100ms-1 mg‡e‡M †U‡ª bi mgvšiÍ v‡j Pjv ïiæ Kij| †Uªb
‡eM, v =? MvwowU‡K KLb wcQ‡b †dj‡e?
 v  d  1 t 3  3t 
dt  3  g‡b Kwi, t mgq ci †Ubª MvwowU‡K GLv‡b,
wcQ‡b †d‡j P‡j hv‡e, Mvwoi mg‡eM, V = 100ms-1
 v  1  3t 2  3 t mgq †Ub KZK… AwZµvšÍ `i~ Z¡, ‡U‡ª bi Z¡iY, a = 10ms-2
3
x  0  1 at 2 mgq, t = ?
 v  t2 3 2

 v  22  3 [t Gi gvb ewm‡q]  x  1 10  t 2
2
 v  7 GKK („Ans.)

8| 54 kmh1 †e‡M PjšÍ GKwU †ij Mvwo‡Z †÷mb †_‡K wKQy `y‡i  x  5t 2... ... ... (1)

0.75ms-2 g›`b m„wóKvix †eKª ‡`Iqvq MvwowU †÷m‡b G‡m †_‡g †Mj| t mg‡q Mvwo KZK… AwZµvšÍ `i~ Z,¡ x  Vt
 x  100t ... ... ... (2)
†÷mb ‡_‡K KZ `~‡i †eªK †`Iqv n‡qwQj Ges MvwowU _vg‡Z KZ

mgq †j‡MwQj? kZ©g‡Z †Uªb hLb MvwowU‡K AwZµg Ki‡e ZLb x  x n‡e|

Avgiv Rvwb, 5t 2  100t

v2 = u22as GLv‡b,  t  100 t  20s (Ans.)
 0  152  2 0.75 s Avw`‡eM, u = 54 kmh-1 5
 s  1515 m
 541000 ms1 11| w¯’ive¯v’ †_‡K Pj‡Z Avi¤¢ K‡i 625m `i~ Z¡ AwZµg Ki‡j GKwU
2 0.75 3600
s  150 m (Ans.) e¯‘i †eM 125ms-1 nj| Z¡iY wbYq© Ki|
=15ms-1
Avevi, v = u  at g›`b, a = 0.75ms-2 Avgiv Rvwb, GLv‡b,
Avw`‡eM, u = 0
 0  15  0.75 t †kl‡eM, v = 0 v2  u 2  2as AwZµvšÍ `~iZ¡ , s = 625m
 1252  0  2  a  625
 t  15 s mgq, t = ?
0.75 miY, s=?  a  1252 ms 2 ‡kl †eM, v = 125 ms-1
2  625 Zi¡ Y, a =?

 t  20s (Ans.) a  12.5ms 2 (Ans.)

9| GKwU e¯‘ w¯i’ Ae¯’vb n‡Z hvÎv ïiæ K‡i c_Ö g †m‡K‡Û 1m 12| 64m DuPz `vjv‡bi Qv` †_‡K 5kg f‡ii GKwU cv_i †Q‡o w`‡j

`i~ Z¡ AwZµg K‡i| cieZ©x 1m `~iZ¡ AwZµg Ki‡Z KZ mgq f~wg‡Z †cuŠQv‡Z Gi KZ mgq jvM‡e?

jvM‡e| GLv‡b, Avgiv Rvwb,

Avgiv Rvwb, GLv‡b,

s1  ut1  1 at12 Avw`‡eM, u = 0 h  ut  1 gt 2 Avw`‡eM, u = 0
2 2 AwZµvšÍ `i~ Z¡ , h = 64m
mgq, t1 = 1s fi, m= 5kg
 1  0  1 a(1)2 miY, s1 =1m  64  0  1  9.8  t 2 mgq, t =?
2 Z¡iY, a=? 2

1 a  64  4.9t 2
2
 t  64  t  3.61s. (Ans.)
 a  2ms2 4.9

GLb cÖ_g †_‡K s2 = (1m+1) =2m `~iZ¡ AwZµg Ki‡Z mgq 13| w¯’i Ae¯’vb n‡Z hvÎv Avi¤¢ K‡i GKwU e¯‘ c_Ö g †m‡K‡Û 2m `~iZ¡
jv‡M = t2
AwZµg K‡i| cieZx© 2m `~iZ¡ AwZµg Ki‡Z e¯w‘ Ui KZ mgq

s2  ut 2  1 at 2 jvM‡e| GLv‡b,
2 2 Avgiv Rvwb,
Avw`‡eM, u = 0
 2  0  1  2  t 2 s1  ut1  1 at 2 mgq, t1 = 1s
2 2 2 1 miY, s1 =1m
Z¡iY, a =?
 t 2  2  2  0  1 a(1) 2
2 2


3| MwZwe`¨v (Dynamics) 3

2 a 15| GKwU cÖv‡mi AbyfywgK cvjvø 96m Ges Avw`‡eM 66 ms-1| wb‡ÿc
2
†KvY KZ?
 a  4ms2
Avgiv Rvwb, GLv‡b,
GLb c_Ö g †_‡K s2 = (2m+2m) = 4m `~iZ¡ AwZµg Ki‡Z
mgq jv‡M = t2 R  vo2Sin 2o Abyfwy gK cvjøv, R = 96 m
g
Avw`‡eM, vo = 66ms-1
AwfKlR© Zi¡ Y, g = 9.8ms-2

s2  ut 2  1 at 2 ev , Sin2θo  Rg wb‡ÿc †KvY,  = ?
2 2
v 2
0

 4  0  1  4 t 2 ev, Sin2o  96  9.8
2 2 662

 t 2  2 ev, 2θo  Sin 1(0.2159)
2

 t 2  2  1.414s ev, 2θo  12.47
‡k‡li 2m `~iZ¡ AwZµg Ki‡Z mgq θo  6.24 (Ans.)

jv‡M, t  t 2  t1  (1.414 1) s  0.414s (Ans.)

14| GKwU e¯‘ c_Ö g `yB †m‡K‡Û 30m I cieZ©x Pvi †m‡K‡Û 16| GKwU e¯‡‘ K 40ms-1 †e‡M Abf~ ywg‡Ki mv‡_ 60° ‡Kv‡Y wb‡ÿc Kiv
nj| mev© waK D”PZv Ges Abyf~wgK cvjvø wbYq© Ki|
150m ‡Mj| Zi¡ Y AcwiewZ©Z _vK‡j e¯‘wU Gi ci GK †m‡K‡Û Avgiv Rvwb,

KZUv c_ AwZµg Ki‡e? GLv‡b, (v o Sin θ o ) 2
Avgiv Rvwb, H
`~iZ¡, s1 = 30m
s1  ut1  1 at 2 mgq, t1 = 2s 2g GLv‡b,
2 1 miY, s2 = (30+150) Avw`‡eM, v0 = 40ms-1
40 Sin 602
 30  u  2  1 a  22 =180m wb‡ÿc †KvY 60º
2 miY, s7 =? H AwfKlR© Zi¡ Y,
2  9.8 g = 9.8ms-2
u  a 15..........(1) mev© waK D”PZv, H = ?
 H  40 Sin 60 2
cÖ_g †_‡K t2= (2+4)= 6 †m‡K‡Û e¯w‘ U hvq Abfy wy gK cvjøv, R = ?
2  9.8
s2=(30+150)m=180m
40  0.86602 2
 s2  ut2  1 at22
2 H
2  9.8
180  u  6  1 a  62
2 34.6408 2

u  3a  30..........(2) H
2  9.8
u  a 15..........(1)
1199 .9850
we‡qvM K‡i, 2a= 15 a  7.5ms2 H
GLb (1) bs mgxKi‡Y a Gi gvb ewm‡q,
2  9.8
u  7.5  15 u  7.5ms1
6 ‡m‡K‡Ûi c‡ii †m‡KÛ A_v© r 7g †m‡K‡Û AwZµvšÍ `~iZ¡,  H  61.22 m (Ans .)
Avevi,

R  v 2 Sin 2θo
0

g

st  u  a (2t 1)  R  402Sin (2  60)
2 9.8

 s7  7.5  7.5 (2 7 1)  R  402 Sin ( 2  60)
2 9.8

 s7  7.5  7.5 13  R  1600 Sin 120)
2 9.8

 s7  7.5  48.75  R  1600  0.86602
9.8
s7  56.25m (Ans)
 R  1385.632
9.8

 R  141.39 m (Ans.)


3| MwZwe`¨v (Dynamics) 4

17| nvB‡Wvª ‡Rb cigvbiy g‡W‡ji GKwU B‡jKUbª GKwU †cÖvU‡bi  y  28.86751346 6.533333345

Pviw`‡K 5.2 ×10 -11 m e¨vmv‡a©i GKwU e„ËvKvi c‡_ 2.18 ×106  y  22.33 m (Ans.)
ms-1 †e‡M c`Ö wÿb K‡i| B‡jKU‡ª bi fi 9.1 ×10-31 kg n‡j

†K›`gª yLx ej KZ? 21| GKwU cÖv‡mi Abfy wy gK cvjvø 79.53 m Ges wePiYKvj 5.3 s n‡j
Avgiv Rvwb, wb‡ÿc †KvY I wb‡ÿc †eM KZ?

F  mv 2 Avgiv Rvwb, GLv‡b,
r R  vo2Sin 2o Abyfwy gK cvjvø , R = 79.53 m
wePiYKvj, T=5.3s
F  9.1 10 -31 (2.18106)2 g wb‡¶c ‡eM, vo = ?
5.2 10-11  79.53  v2oSin 2o wb‡¶c †KvY,  = ?

 F  8.316108 N (Ans.) 9.8

18| 0.250kg f‡ii GKwU cv_i LÛ‡K 0.75m j¤^v GKwU myZvi  vo2Sin2o  779.394.. ... (1)

GK cÖv‡šÍ †eu‡a eË„ vKvi c‡_ cÖwZ wgwb‡U 90 evi Niy v‡j myZvi Dci Aevi, T  2voSino
g
KZ Uvb co‡e| GLv‡b,
Avgiv Rvwb,  5.3  2voSino
fi, m = 0.250 kg 9.8
F  m2r e¨vmva,© r = 0.75 m
 F  m   2πn 2  r mgq t = 1 min.  2voSino  51.94 ... ... ... (2)
(1) bs mgxKiY‡K (2) bs mgxKiY Øviv fvM K‡i cvB,
t = 60s.
cvKmsL¨v, n = 90 cvK| vo2Sin 2o  779.394
 F 0.25 23.1416902 0.75 Uvb, F = ? 2voSino 51.94
 60 

 F  16.65 N (Ans.)  v 2 2Sin oCoso  779.394
o
19| 9.2 ms-1 †e‡M GKwU ÿz`ª e¯‘‡K Lvov Dc‡ii w`‡K wb‡ÿc
Kiv nj| GwU KZ mgq c‡i f-~ c„‡ô wd‡i Avm‡e? 2voSino 51.94

 v0Coso  15 ... ... .. (3)

Avgiv Rvwb, GLv‡b, (2) bs mgxKiY‡K (3) bs mgxKiY Øviv fvM K‡i cvB,
Avw`‡eM, vo = 9.2 ms-1
T  2voSino 2voSino  51.94
g wb‡¶c †KvY, 0º v0Coso 15
AwfKlR© Zi¡ Y,
 T  2  9.2  Sin90 g = 9.8ms-2  tan o  3.463
9.8 DÌvb cZ‡bi †gvU 2

 T  2  9.2 1 mgq T =?  tan o  1.732
9.8
 o  tan1 1.732
 T  18.4
9.8  o  60(Ans.)

T  1.877s (Ans.) (3) bs mgxKi‡Y 0 Gi gvb ewm‡q cvB,

v0Cos60  15

20| Abyfywg‡Ki mv‡_ 30°†KvY f~-cô„ †_‡K 50ms-1 †e‡M GKwU  v0  1  15
2
e‡y jU †Qvov nj| e‡y jUwU 50m `~‡i Aew¯’Z GKwU †`Iqvj‡K KZ

D”PZvq AvNvZ Ki‡e|  v0  30ms 1 (Ans.)

Avgiv Rvwb, GLv‡b,

y  (tan 0 )x  2(v0 g x2 Avw`‡eM, vo = 50 ms-1 22| GKwU ej‡K fw~ gi mv‡_ 30°†KvY K‡i Dc‡ii w`‡K wb‡ÿc Kiv
cos 0 )2 n‡j GwU 20m `‡~ i GKwU `vjv‡bi Qv‡` wM‡q coj| wb‡ÿc we›`y †_‡K
wb‡¶c †KvY, º
AwfKl©R Zi¡ Y,

g = 9.8ms-2 Qv‡`i D”PZv 5m n‡j ejwU KZ †e‡M †Qvov n‡qwQj|

 y  (tan30 )x  g (50)2 Abfy ywgK `i~ Z,¡ x=50m Avgiv Rvwb,
cos30 Dj¤^ `~iZ,¡ y=?
2(v0 )2 g x2 GLv‡b,
y  (tan 0 )x  cos 0 )2
2(v0 wb‡¶c †KvY, º
 y  (tan30)50 g (50)2 AwfKlR© Zi¡ Y,
2(v0 cos30 )2 g = 9.8ms-2
Abyfwy gK `i~ Z,¡ x=20m
 y  0.57735026950 9.8 (50)2 5  tan3020 9.8 (20)2
2(50 0.86602540)3 2 2v02 cos2 30 Dj¤^ `~iZ,¡ y=5m

Avw`‡eM, vo =?


3| MwZwe`¨v (Dynamics) 5

9.8 400 24| GKwU MvÖ ‡gv‡dvb †iKW© cwÖ Z wgwb‡U 45 evi N‡y i| Gi †K›`ª †_‡K
 5  0.57735026920 
9cm `‡~ i †Kvb we›`iy `æª wZ KZ?
2 v02  0.75
v  r
3920 GLv‡b,
 5  11.54  v02 1.5
 v  2n r mgq, t = 1m =60s
 3920  6.54 t cvKmsL¨v, n=45
e¨vmva,© r =9cm=0.09m
v 2  1.5  v  2  3.14  45  0.09 `ªæwZ, v =?
0 60

 v 2  3920 v0  20ms1(Ans.)  v  0.42ms1 (Ans.)
0 6.54 1.5

23| GKRb †jvK 48 ms-1 †e‡M GKwU ej Lvov Dc‡ii w`‡K

wb‡ÿc K‡i| ejwU KZ mgq k‡~ Y¨ _vK‡e Ges m‡ev© ”P KZ Dc‡i

DV‡e?

Avgiv Rvwb, GLv‡b,

T  2voSinθo  †eM, v0 = 48 ms-1
g wb‡¶c †KvY, =º

T 2  48Sin90 DÌvb cZ‡bi †gvU mgq,T =?
9.8 D”PZv, H =?

 T  2  481
9.8

T  9.795 s. ( Ans.) 

Avevi,

H  vo2Sin 2o
2g

 H  482 (Sin90)2 
2  9.8

 H  117.5m (Ans.) 


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