Transcription

1 Collisions. In had on lastic collision of two bodis of qual ass ) Th fastr body spds up furthr and th slowr body slows down. ) Th fastr body slows down and th slowr body spds up. 3) Both of th abov. 4) Non of th abov.. Whn two bodis of sa ass undrgo had on lastic collision, ) Thir vlocitis ar intrchangd ) Thir spds ar intrchangd 3) Thir onta ar intrchangd 4) All th abov ar tru 3. A havir sphr oving astward with a crtain vlocity v collids with a lightr sphr at rst. If it is prfct lastic had on collision, thn aftr collision ) Havir sphr ovs wst ward with sa spd ) Havir sphr cos to rst 3) Lightr sphr ovs astward with vlocity v approxiatly 4) Lightr sphr ovs astward with vlocity approxiatly 4. Choos th corrct statnt ) In an lastic collision, ontu is consrvd but K.E. is not consrvd. ) In an lastic collision, K.E. is consrvd but ontu is not consrvd. 3) In an inlastic collision, both ontu and K.E. ar consrvd. 4) In an inlastic collision, ontu is consrvd but K.E. is not consrvd. 5. Choos th fals statnt. ) In a prfct lastic collision, th rlativ vlocity of approach is qual to th rlativ vlocity of sparation. ) In an inlastic collision, th rlativ vlocity of approach is lss than th rlativ vlocity of sparation. 3) In an inlastic collision, th rlativ vlocity of sparation is lss than th rlativ vlocity of approach. 4) Non of th abov.

2 6. Whn a ball hits a floor and rbounds aftr an inlastic collision ) Th ontu of th ball just bfor collision is qual to its ontu just aftr collision. ) Th total chanical nrgy of th ball just bfor collision is qual to its total chanical nrgy aftr collision. 3) Th total ontu of th ball and arth is consrvd. 4) All th abov ar tru. 7. Cofficint of rstitution dpnds upon ) Th rlativ vlocitis of approach and sparation. ) Th asss of th colliding bodis. 3) Th atrials of th colliding bodis. 4) All th abov. 8. Th collision in which th rlativ vlocity of approach bfor collision is qual to rlativ vlocity of sparation aftr collision is ) Copltly inlastic collision ) Elastic collision 3) Inlastic collision 4) Both lastic and inlastic collision 9. A body collids had on and lastically with anothr idntical body at rst thn aftr collision ) First body cos to rst, and thn scond body bgins to ov with th initial vlocity of first body. ) Both th bodis ov with sa initial vlocity of first body. 3) First body rvrsd in dirction and ov with sa spd but scond body continus to b at rst. 4) Both th bodis co to rst aftr collision. 0. In an inlastic collision btwn two bodis, th physical quantity that is consrvd is ) Kintic nrgy ) Montu 3) Potntial nrgy 4) Kintic nrgy and Montu

3 . A: Collision btwn two particls is not ncssarily associatd with physical contact btwn th. R: Only in physical contact, ontu transfr taks plac. ) Both (A) and (R) ar tru and (R) is th corrct xplanation of (A). ) Both (A) and (R) ar tru and (R) is not th corrct xplanation of (A). 3) (A) is tru but (R) is fals. 4) (A) is fals but (R) is tru.. Match th following. List - I List - II a) Elastic collision ) 0 b) Inlastic collision f) 0 < < c) Explosion g) d) Plastic collision h) Final K.E. > Initial K.E. ) a-, b-f, c-g,d-h ) a-g,b-,c-f,d-h 3) a-h,b-g,c-f,d- 4) a-g, b-f, c-h, d- 3. Match th following. List - I List - II a) Ipuls ) Ara undr f-t graph b) + c) 4 ( + ) f) Elastic collision btwn siilar bodis g) Fraction of K.E rtaind in an lastic collision d) Intrchang of vlocitis collision h) Fraction of K.E transfr in an lastic ) a-h, b-g,c-f,d- ) a-f,b-g,c-h,d- 3) a-, b-f, c-h, d-g 4) a-,b-g,c-h,d-f 4. A prfctly lastic ball P of ass oving with vlocity v collids lastically with thr xactly siilar balls P, P3, P4 lying on a sooth tabl as shown. Vlocitis of th four balls aftr th collision ar ) v, v, v, v, ) 0, v, 3v, 4v 3) 0, 0, 0, v 4) 0, 0, 0, 0

4 5. (A): Whn a ball is thrown up, th agnitud of its ontu dcrass and thn incrass. This violats th ontu consrvation principl. (R): Th principl of ontu consrvation applis to th ntir syst, hr arth-plus-ball syst. () Both A and R ar tru and R is th corrct xplanation of A. () Both A and R ar corrct and R is not th corrct xplanation of A. (3) A is tru but R is fals. (4) A is fals but R is tru. 6. (A): Whn stationary bob xplods into two pics thir spds ar in th invrs ratio of thir asss. (R): Explosion dos not violat Law of consrvation of linar ontu. () Both (A) and (R) ar tru and (R) is th corrct xplanation of (A). () Both (A) and (R) ar tru and (R) is not th corrct xplanation of (A). (3) (A) is tru but (R) is fals. (4) (A) is fals but (R) is tru. 7. A) Whn two sphrs collid ontu transfr taks plac along noral to tangnt drawn at contact surfac. B) Whn a ball hits a wall at an angl to horizontal its ontu along th wall rain constant. C) Whn a ball bouncs n tis bfor coing to rst th total ti lapsd is t h + g () A, B ar tru () A, C ar fals (3) A, B, C ar tru (4) A, B, C ar fals 8. A) A 4kg body collids lastically with kg stationary body. (/9) of nrgy is rtaind by it. B) Whn a nutron collids lastically with stationary nuclus of ass nubr A 4A fraction of nrgy rtaind by it is ( A + ). C) A odrator is chosn in nuclar ractor in such a way that atoic ass of odrator is coparabl to that of nutron. ) A, B ar tru ) A, C ar fals 3) A, B, C ar tru 4) A, B, C ar fals

5 9. A bullt of ass 5 g. lavs a rifl with a vlocity of with a vlocity 5 s. Find th ass of th rifl. 500 s. Th riffl rcoils ) 00 kg ).5 kg 3).5 kg 4) 5 kg 0. A boy of ass 40 kg jups off a boat with a vlocity of3 s. With what ) ontu dos th boat ov? 0 kg. s ) 0 kg. s 3) 5 kg. s 4) 5 kg. s. A nuclus of ass nubr 'A' originally at rst its an α particl with a spd 'v' ) th rcoil spd of th daughtr nuclus is ν 4 A ) 4ν A + 4 3) ν A + 4 4) 4ν A 4. A gun firs a bullt of ass 50 g with a vlocity of ass 30 s. Bcaus of this, th gun is pushd back with a vlocity ofs. Th ass of th gun is ) 5 kg ) 30 kg 3).5 kg 4) 0 kg 3. A body of ass kg aks an lastic collision with anothr body at rst and continus to ov in th original dirction at a spd qual to /3 of its original spd. Th ass of th scond body is ) kg ) 3 kg 3) kg 4) 4 kg 4. Considr th following statnts A and B. Idntify th corrct choic in th givn answr A: In a on - dinsional prfctly lastic collision btwn two oving bodis of qual asss, th bodis rly xchang thir vlocitis aftr collision B: If a lightr body at rst suffrs prfctly lastic collision with a vry havy body oving with a crtain vlocity, aftr collision both travl with sa vlocity ) A and B ar corrct ) Both A and B ar wrong 3) A is corrct B is wrong 4) A is wrong B is corrct 5. A car of ass 400 kg travlling at 7 kph crashs a truck of ass 4000 kg and travlling at 9 kph in th sa dirction. Th car bouncs back with a spd of 8 kph. Th spd of th truck aftr th ipact is ) 9 kph ) 8 kph 3) 7 kph 4)36 kph 6. A body P oving with a vlocity of 0 s collids with anothr body Q of sa ass at rst. Aftr collision P cos to rst. What is th vlocity of th body Q? ) 0 s ) 0 s 3) 30 s 4) 5 s

6 7. A ball of ass 'M' oving with a vlocity V collids had on lastically with anothr body of th sa ass 'M' oving with a vlocity- V dirction. Aftr th collision ) Th vlocitis ar xchangd by th two balls. ) Both th balls co to rst. 3) Both of th ov at right angls to th original lin of otion. in th opposit 4) On ball cos to rst and th othr ball travls back with a vlocity v. 8. Considr th following statnts A and B and idntify th corrct answr: A: In an lastic collision, if a body suffrs a had on collision with anothr of sa ass at rst, th first body cos to rst whil th othr starts oving with th vlocity of th first on. B: Two bodis of qual asss suffring a had-on lastic collision rly xchang thir vlocitis.. A and B ar tru.. A and B ar fals. 3. A is tru but B is fals. 4. A is fals but B is tru. 9. A block of wood of ass 9.8 kg is suspndd by a string. A bullt of ass 00 g striks horizontally with a vlocity of to which th block ris is ( g 0 s ) 00 s and gts ibddd in it. Th hight ) 0. ) 0. 3) 0.3 4) A Kg ball is oving at collision thy ov togthr with 0 s and collids with anothr Kg ball at rst. Aftr ) In th opposit dirction ) In th sa dirction 3) In th opposit dirction 4) In th sa dirction 3. A bullt of ass 'x' ovs with a vlocity y, hits a woodn block of ass z at rst and gts bddd in it. Aftr collision, th woodn block and bullt in it ovs, th vlocity is ) x y x + z ) x + y y x 3) z y x + y 4) x + y y z 3. A rubbr ball drops fro a hight h and aftr rbounding twic fro th ground, it riss to h/. Th co - fficint of rstitution is ) ) / 3) /4 4) /6

7 33. A body droppd frly fro a hight h on to a horizontal plan, bouncs up and down and finally cos to rst. Th cofficint of rstitution is. Th ratio of vlocitis at th bginning and aftr two rbounds is ) : ) : 3) : ² 4) ² : 34. A ball is droppd fro a hight h abov a til floor and rbounds to a hight of 0.64h. Th cofficint of rstitution btwn th ball and th floor is ) 0.64 ) 0.8 3) /0.64 4) / In th abov probl loss in K.E during collision is 4 ) KJ ).33 J 3).33 KJ 4).33 0 J 36. A oving body aks a prfctly inlastic collision with a scond body of qual ass at rst K.E lost during collision is of initial K.E. ) /4 ) / 3) 4) A particl falls fro a hight 'h' upon a fixd horizontal plan and rbounds. If '' is th cofficint of rstitution, th total distanc travlld bfor it cos to rst is ) + h ) h + 3) h + 4) h Th objct at rst suddnly xplods into thr parts with th ass ratio ::. Th parts of qual ass ov at right angls to ach othr with qual spds. Th spd of th third part aftr th xplosion will b ) V ) V/ 3) V/ 4) V 39. A body of ass striks anothr body at rst of ass. Assuing th ipact 9 to b inlastic th friction of th initial kintic nrgy transford into hat during th contact is ) 0. ) 0. 3) 0.5 4) A rifl of 0kg ass can fir 4 bullts pr scond. Th ass of ach bullt is and its final vlocity is 400s. Thn what forc ust b applid on th kg rifl so that it dos not or backwards whil firing th bullts ) 80 N ) 8 N 3) - N 4) -56N

8 4. A projctil of ass 50 kg is shot vrtically upwards with an initial vlocity of 00s -. Aftr 5 sconds it xplods into two fragnts, on of which having ass 0 kg, travls vrtically up with a vlocity of 50s -. Th vlocity of th othr fragnt at that instant is ) 00s - ) 50s - 3) -50s - 4) -5s - 4. A tnnis ball bouncs down a flight of stairs, striking ach stp in turn and rbounding to th half of hight of th stp. Th cofficint of rstitution is ) / ) 3) / 4) 43. A ball is droppd fro a hight h on a floor of cofficint of rstitution. Th total distanc covrd by th ball just bfor scond hit is ) h( ) ) h( + ) 3) h( ) + 4) 44. In two sparat collisions, th cofficint of rstitutions and S ar in th ratio 3:. In th first collision th rlativ vlocity of approach is twic th rlativ vlocity of sparation, and thn th ratio btwn rlativ vlocity of approach and th rlativ vlocity of sparation in th scond collision is ) :6 ) :3 3) 3: 4) 6: 45. A sphr of ass oving with constant vlocity u, collids with anothr stationary sphr of sa ass. If is th cofficint of rstitution, th ratio of th final vlocitis of th first and scond sphr is ) + ) + 3) h 4) Two balls of sa ass ach ar oving with sa vlocitis v on a sooth surfac as shown in figur. If all collisions btwn th ass and with th wall ar prfctly lastic th possibl nubr of collisions btwn th bodis and wall togthr is /4 ) ) 3) 3 4) Infinity

9 47. A shll is fird fro gun with a vlocity of 300s - aking an angl 60 0 with th horizontal. At th highst point, it bursts into two pics whos asss ar in th ratio : 3. Th sallr pic rtracs its path aftr th xplosion and ntrs th gun. Find th vlocity of th largr pic, idiatly aftr th xplosion. ) 0s - ) 00s - 3) 50s - 4) 300s A tst tub of ass 0 g is filld with a gas and fittd with a stoppr of g. It is suspndd horizontally by ans of a thrad of lngth and hatd. Whn th stoppr kicks out, th tub just coplts a circl in vrtical plan. Th vlocity with which th stoppr is kickd out is ) 7s - ) 0s - 3) 70s - 4) 0.s A oving sphr P collid anothr sphr Q at rst. If th collision taks plac along th lin joining thir cntr s of ass such that thir total kintic nrgy is consrvd and th fraction of K.E. transfrrd by th colliding particl 8 9 ass of P and th ass of Q bar a ratio ) 8 : 3 ) 9: 8 3) : 3 4) : is, th 50. A particl striks a horizontal friction lss floor with a spd 'u' at an angl ' θ ' with th vrtical and rbounds with a spd v at an angl ' α ' with th vrtical. Find th valu of 'v' if '' is th cofficint of rstitution. ) 3) v u θ θ sin + cos ) v u θ θ v u θ + θ cos + tan 4) v u cot θ + cos θ 5. 0 bullts ach of ass 0 g ar fird in succssion into a block of ass 450 g at rst. If vlocity of ach bullt is 0 s - and all th bullts ar bddd in th block, th vlocity of th block is ) 0s - ) 0s - 3) 5s - 4) 30s - 5. Two stl sphrs approach ach othr had-on with th sa spd and collid lastically. Aftr th collision on of th sphr's of radius r cos to rst. Th radius of th othr sphr is r ) /3 (3) ) 3 r 3) 9 r cos sin 4) (3) / r

10 Ky ) ) 4 3) 3 4) 4 5) 6) 3 7) 3 8) 9) 0) ) 3 ) 4 3) 4 4)3 5)3 6) 7) 3 8) 3 9) 0) ) 4 ) 3 3) 3 4) 3 5) 3 6) 7) 8) 9) 30) 3) 3) 3 33) 3 34) 35) 4 36) 37) 38) 39) 40) 4 4) 4 4) 43) 44) 4 45) 46) 3 47) 3 48) 3 49) 4 50) 5) 5) v + v P u boat +. 0 v v. v + MV 0 3. K. E 00 K. E v u + u u + u v + v 6. u + u v + v 7. u u v + v 9. h v g v + v 30. Vc + Hints

11 v + v 3. Vc + 3. h h 33. v n n. 34. h h v u K. E ( + ) u K. E ( + ) d h+ h h + + ; n h h 38. Vi + Vj + P 0 P V ( i + j) P V 3 V 3 3 P V V n u u KEtransford + KE u nu F t ( ) 4. V u gt 00 (9.8) MV v + v V V V V s h h n 43. h h h n 44. : 3: h V V 5 U V

12 V U V : 3: U V U U V : 3: 6 : 45. V u V ( + ) 0 + u + ( + ) V u + u + + ( + ) V u + u + + With u 0 and 4 ( u cos θ ) ( u cos θ ) + 3V 3V 5u cosθ ( M + )0 v M 5gl M 5gl v ( 0 0, M Kg Kg 49. Kintic nrgy rtaind is V ( V sin α) + ( V cos α ) V ( u sin θ ) + ( u cos θ ) 5. u θ + θ cos sin ( ) 0x0x v c vc 0s

13 5. v 0 3 R 3. R 3 3 r R 3 /3