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286 JEE Main Physics 21. A body in equilibrium may not have Ial monestum (cl acceleration 27. When two hlocks A and l coupled by a spring frietaonlesa table are atretehed and then reled then lat etie eney t baly at any istast sher nlg imenicly moportional to their mases (b kinetir ergy of body at any instant may y Inversely paoportional to their ans KE of th velocity kinetic encry 22. A bomb is kept stationary at a point. It uddenly explodes inte two fragments of massea lg and 3g. The total kinetie energy of the fragmenta is 8.4x 10 What in the kinetic energy of the smaller fragment? fal 15 10 lel 4.10J 23. In the given figure, two bodies of maas m, and my are connected by manaless spring of force constant i and are placed on a amooth aurface (ahown in figure), then when spring h unies bl 3.5 x 10 (il 52 1o ms of Idt lhoth (b) and d ae comert 28. An iaolated partirle of mass i moving in a horiontal plane ryl, along the e-axie, at a ertan heught above the ground. It uddenly explades two fragments of mases m and Jm/4. An instart Inter. the amaller fragment ie at y 15 on. The lurger fragment at this ntant in at laly5cm Idy em 29. A bomb a reit explodes in air into tww egu fragmenta one of the fragmenta i mg ertically upwarts with velncity w, then the ather frogment will move Tal vertically up with velocity va vertically own with velncity Iel in ahitany diiection with velocity un horiontaly with velacity my tal the acceleration of centre of mass mit be m ot eery instant (bly20 m th) the acceieratlan of eenne of mas may be aero at every Instant 30 c el the system.aways mis in rest di None of the above 24. A particle moven in the y plane under the action of a force uch that the value af ita linoar momeotum p at ny time t in p,-eont, p, -Raint The wngle between Fand p at a given tume t will be al 90 25. Aset of n dentical cubieal hlocks lies nt rest parallal to each othar along a line on a mooth horiuontal nurface. The separation between the near surllaces of any two adjacent. bloeka ta L The block at one end is given a speed o towarda the nest one ist timet0 All eolliaions are eoimpletely elantin. Then Collision 30. Whieh of the following is not a perfectly int collon Sing of two glas ball A buller nng a h of anat An election captied by aa poton A nan apinj onto a ning car 31. A ball of mans hovin with velicity esllide anither ball nf'mana 2 and atieha to i. The vel ol the final aytem in lal v m -F al the last bock sturts movng at timet la- (b) the l lock starts veg at inet W the ome of eus of the syvem il havea final speedy l the centre of mass of tht ytem will hove a final peed vin 32. An example of inelastie tollialun is A witteg f opartcle fim a den th) collidon of ideal p maleeules l colls f wn stert lll y on act ll collison af a bulles with a wonden blick 26. T'wo bloekkn of masses m and my are nnted by a maalesa pring and pluced at umooth murtace. The ring initinlly stretehed and releaned. Then Ial the momentum af each article temulni mant sepaily d the magrituale of inuminmum of both beodies are same to coch other Id the mechutical eneny of ayskem mai cemtant d hoth and ld ae cumect 33. In an olaatar enlliaion lalonly Kt tn is co ned Btouly umntn mend id both Kanaliimi ate cumad Tl ther K mr mument is eel