51. Elektrijada, Kopaonik

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may 11. 51. Elekrijada Kpanik Tes in Physics 1. A mbile is frmed by suppring fur meal buerflies f equal mass m frm a sring f lengh L.

1 may Elekrijada Kpanik Tes in Physics 1. A mbile is frmed by suppring fur meal buerflies f equal mass m frm a sring f lengh L. The pins f suppr are evenly spaced a disance l apar as shwn in Figure -1. The sring frms an angle Θ 1 wih he ceiling a each end pin. The disance D beween he end pins f he sring is: Figure -1 L 1 1 θ 1 5 L 1 csθ1 + cs arcg cg θ L 1 D csθ1 + cs arcg g θ a) D csθ + cs arccg g( ) + 1 b) D { csθ + cs( arcg( g( θ ))) 1} L c) D ( ) d) D { csθ + cs( arcg( g( θ ))) 1} e) ( ) L A wearhuse wih a widh a5m and a high ha/ is lcaed n a fla hriznal sil (Figure -). The rf heigh is small cmpared he widh f he building. The minimum velciy v in which an bjec shuld be hrwn frm he grund s ha i flies ver he warehuse and he relevan angle are (g1m/s ): Figure - Srana 1

may 11. 51. Elekrijada Kpanik a) v 1m 6 b) v 11m 45 c) min min 9m d) v 57 e) v min min 1m 75 v min 15m.

61 μald.47 fr aluminum n seel and μ Cus.5 μ Cud.6 fr cpper n seel respecively. D hey sar mve nce any hlding mechanism is released? Wha is he ensin in he sring?

2 may Elekrijada Kpanik a) v 1m 6 b) v 11m 45 c) min min 9m d) v 57 e) v min min 1m 75 v min 15m. A m 1 kg aluminum blck and a m 6kg cpper blck are cnneced by a ligh sring ver a fricinless pulley. They si n a seel surface as shwn in Figure - and θ. The saic and dynamic fricin cefficiens are μ Als.61 μald.47 fr aluminum n seel and μ Cus.5 μ Cud.6 fr cpper n seel respecively. D hey sar mve nce any hlding mechanism is released? Wha is he ensin in he sring? Figure - a) yes S 1N b) yes S 1N c) n S 1N d) n S. 5N e) n S 7N 4. A puck wih a mass f 8g and a radius f 4cm slides alng an air able a a velciy f 1.5m/s as shwn in Figure -4. makes a glancing cllisin wih a secnd puck having a radius f 6cm and a mass f 1g (iniially a res) such ha heir rims jus uch. Because heir rims are caed wih insan-acing glue he pucks sick geher and spin afer he cllisin (Figure -4). The sysems cener f mass velciy v cm and he angular velciy abu he cener f mass ω immediaely afer cllisin are: Figure -4 а) v cm 9m ω 571rad / s b) v cm 6m ω 947rad / s c) v cm 6m ω 69rad / s d) v cm 4m ω 15.7rad / s e) v cm m ω 1rad / s Srana

may 11. 51. Elekrijada Kpanik 5. A sysem cnsiss f a ball resing a ne and f a unifrm bard f lengh l hinged a he her end and elevaed a an angle θ/4 (Figure -5).

3 may Elekrijada Kpanik 5. A sysem cnsiss f a ball resing a ne and f a unifrm bard f lengh l hinged a he her end and elevaed a an angle θ/4 (Figure -5). A ligh cup is aached he bard a r c s ha i will cach he ball when he suppr sick is suddenly remved. The ball will fall in he cup when he bard is suppred a: Figure -5 a) r c l b) r l c c) r c l d) here is n such r c e) r c l 6. A sphere f mass M and radius R has a nnunifrm densiy ha varies wih r he disance frm is cener accrding he expressin Ar fr r R. The dependence f he graviainal field inensiy G n he radial crdinae r is: γmr a) G R r γmr d) G r R r r r r [ R] ( R [ R] ( R γmr r [ R] 5 b) G R r ( R r γm r [ R] Rr e) G r ( R r γmr r 4 c) G R r r [ R] ( R Srana

4 may Elekrijada Kpanik 7. A ligh cubical cnainer f vlume a is iniially filled wih a liquid. The mass f he liquid in he filled cnainer is m. The cnainer is iniially suppred by a ligh sring f lengh L frm a pendulum (L >>a). The liquid is allwed flw frm he bm f he cnainer a a cnsan rae dm/db. The perid T as a funcin f ime is: L m L bl m a) T g b) T 1+ b g ma b L a ba m c) T 1+ g L m L d)sisem nije linearni harmnijski scilar b L ba m e) T 1 g m L b 8. Tw waves are described by he equains: ( x ) 5sin( x ) y 1 1 and y x 1cs x 1 ( ) ( ) where x is in meers and is in secnds. The ampliude y r and phase ϕ f he resuling sinusidal wave are: a) y 5 ϕ 15 b) r d) y 5 5 ϕ 5 e) r y r 5 ϕ c) 6 5 ϕ y r y r 5 ϕ 9. A ank wih waer slides dwn an inclined plain f angle. f he ank has accelerain am/s he angle frmed by he waer surface and he inclined surface is: a) 6 b) 61 c) 1 d) 1 e) 1. Tw pened cylindrical reservirs wih diameers D 1 m and D 4m sand n a hriznal surface. The reservirs are in uch by heir laeral sides. Jus abve he bm f he reservirs a he place where hey uch here is a small circular aperure wih diameer d1cm which allws he ransfusin f liquids sred in he reservirs. f he liquid level in he firs reservir is H and he secnd reservir is empy he ime τ required fr liquid levels in reservirs becme equal is: Srana 4

5 may Elekrijada Kpanik a) τ 9867s b) τ 16154s c) τ 71s d) τ s e) τ 11s 11. An elecric curren f inensiy 1 1A flws hrugh a ungsen wire in a vacuum packed ligh bulb. The wire has a emperaure T 1 1K. When he curren is increased A he bulb pwer becmes 5 imes higher. The ungsen wire is cnsidered as a gray bdy wih emissin cefficien ϵ independen f emperaure. The specific resisance f ungsen wire a emperaure T 1 is 1 571Ωm. The wire emperaure T ha crrespnds he curren and he specific resisiviy a his emperaure are: a) T 67K Ωm b) T 5K Ωm c) T K Ωm d) T K 95 1 Ωm e) T 67K Ωm 1. The chemical cmpsiin f he amsphere is changed wih aliude because he varius mlecules have differen masses. Saring frm he expressin fr he pressure gradien: dp dz m where m is he mass f he single mlecule and n is heir cncenrain deermine (in percens) fr hw much is he rai f xygen nirgen mlecules changed beween 1km and see level. Assume a unifrm emperaure f K and ake he mlecular masses be g/ml fr xygen (O ) and 8g/ml fr nirgen (N ) (N A 6 1 k B m kg/s K). a) δ 851% b) δ 984% c) δ % d) δ 984% e) δ 851% gn 1. On a cld winer day a man pus in his pcke m 1 9g f cpper cins (c Cu 85J/kg C) a emperaure 1-1. The pcke already cnains m 14g f silver cins (c Ag 5J/kg C) a emperaure. f he emperaure f he cpper cins is increasing wih a cnsan rae f b Cu.5 C/s wih wha rae is he emperaure f he silver cins changing? Calculae he change in enrpy ΔS f he sysem. Neglec energy ransferred he surrundings. a) 5; S 54 J C b) 47; S 184 J C c) 19; S 54 J C d) 5; S 184 J C e) 5; S 184 J C Srana 5

may 11. 51. Elekrijada Kpanik 14. Figure -14 represens n ml f an ideal mnamic gas being aken rugh a cycle ha cnsiss f w ishermal prcesses a emperaures T i and T i and w cnsan-vlume prcesses.

6 may Elekrijada Kpanik 14. Figure -14 represens n ml f an ideal mnamic gas being aken rugh a cycle ha cnsiss f w ishermal prcesses a emperaures T i and T i and w cnsan-vlume prcesses. The efficiency f an engine peraing in his cycle is: Figure -14 a) η 449% b) η 49% c) η 15% d) η 7% e) η 619% 15. A rearview mirrr in cars cnsiss f a reflecive caing n he back f a recangular glass prism wih angle and index f refracin n. n he day seing he rearview mirrr is verical and he figure is frmed by he ligh refleced frm he back surface (Figure -15). The nigh seing grealy diminishes he inensiy f image in rder ha lighs frm railing vehicles d n blind he driver. n his case he rearview mirrr is raed s ha he image is frmed frm he ligh refleced frm he frn surface (Figure -15). The angle θ fr wich he rearview mirrr is raed a nigh is: Figure -15 Srana 6

7 may Elekrijada Kpanik a) θ ( n 1) b) θ ( n 1) c) θ n d) θ ( n 1) e) θ ( n + 1) 16. A gld fish is swimming inside a spherical plasic bwl wih radius R15cm filled wih waer ha has index f refracin n 1.. f he gldfish is lcaed 1cm frm he wall f he bwl n a hriznal axis ha ges hrugh he is cener f where des i appear an bserver uside he bwl? a) l 9cm b) l 6 45cm c) l 1cm d) l 1 cm e) l cm 17. Tw radi anennas separaed by m as shwn in Figure -17 simulaneusly bradcas idenical signals a he same wavelengh. The anennas are lcaed a disance 1m frm he rad. A radi in a car raveling alng he rad saring frm he pin O fr he firs ime receives srng signal a a disance m frm his pin. The wavelengh f he radi signal is: Figure -17 a) λ 6m b) λ 58m c) λ m d) λ 11646m e) λ 6m 18. Three linear plarizers are placed in line ne afer he her as i is shwn in Figure -18. Transmissin axes f he firs and hird plarizer are perpendicular each her. The secnd plarizer is raing arund cenral axis wih cnsan angular velciy ω. The ransmissin axis f he secnd plarizer iniially cincides wih ransmissin axis f he firs plarizer. f unplarized ligh wih inensiy i is inciden n he lef disk he inensiy f he beam emerging frm he righ disk is: Srana 7

8 may Elekrijada Kpanik Figure -18 i i i a) ( 1+ cs 4ω ) b) ( 1 cs 4ω ) c) ( 1+ sin 4ω ) 8 8 i i 1+ cs 4ω e) sin 4ω 16 8 d) ( ) ridium nucleus makes a ransiin frm primary an excied sae emiing a phn f energy 1keV. Find he velciy v f he nucleus afer he ransiin if is mass is. 1-5 kg?. Radiacive ispe X ransfrms he ispe Y hrugh N 79 alpha and N bea minus ( - ) decays. The number f realized and - decays is: a) N N 1 b) N N c) N N N N d) N 1 4 e) N 4 Ne: Each ask carries 5 pins. Only crrecly circled reply wih deailed prcedure and adequae explanain will be marked wih a full number f pins. Fr incrrecly circled reply prcedure is n aken in accun. Srana 8

AP Physics 1 MC Practice Kinematics 1D

AP Physics 1 MC Practice Kinematics 1D AP Physics 1 MC Pracice Kinemaics 1D Quesins 1 3 relae w bjecs ha sar a x = 0 a = 0 and mve in ne dimensin independenly f ne anher. Graphs, f he velciy f each bjec versus ime are shwn belw Objec A Objec