2010 Sectional Physics Solution Set

Transcription

1 . Crrec nwer: D WYSE CDEMIC CHLLENGE Secnl hyc E 00 Slun Se y 0 y 4.0 / 9.8 /.45 y. Crrec nwer: y 8 0 / 8 /. Crrec nwer: E y y 0 ( 4 / ) ( 4.9 / ) 5.6 y y 4. Crrec nwer: E 5. Crrec nwer: The e rce c n bh puck hrugh he e dnce, he e un wrk dne n bh puck reulng n he e chnge n knec energy. 6. Crrec nwer: C ne n ne n M M M M 450 N T N T 50 N 900 N 50 N T 650 N 50 N 50 N 900 N

2 7. Crrec nwer: 8. Crrec nwer: 600 k 600 k Tl e 5 h 00 k / h 00 k / h Tl d n ce rveled 00 k ve 40 k / h Tl e 5 h M 9. Crrec nwer: E ( 60 kg) (9.8 / ) [ dwn] rcn [ up] ( 60 kg)( / )[ dwn] ( 60 kg) (9.8 / ) [ up] rcn [ up] ( 60 kg)( / )[ up] ( 60 kg) (9.8 / ) rcn ( 60 kg)( / ) rcn 468 N energy pwer energy energy e e 0. Crrec nwer: C r rence nn-cnervve rce nce he un wrk dne by h rce depend upn he ph ken nd n ju he end pn he ph.. Crrec nwer: D KE v.5 KE v 54 J kg.5 6 /. Crrec nwer: E The ne pule cng n n bjec equl he CHNGE n enu he bjec nl enu nl enu. Nne he nwer re crrec.

3 . Crrec nwer: gr cenener nd nd nd ec ec ec ceneer ceneer [ dyne] gr 4. Crrec nwer: C Cnvecn 5. Crrec nwer: M 9 r M M 8 M M, rdu M M/, rdu / 6. Crrec nwer: D g ( 7M e ) ( ) G 7GM e ( / ) e 7. / 4 e 4 7. Crrec nwer: D ( 50 N )( un) ( W )( un) W N 50. N C.G. 8. Crrec nwer: W rev π rd v ω /.0.0 ( ) ( ) Crrec nwer: C Ung cnervn ngulr enu, I I ω I ω Iω ω ( I )( rev /.50 ) I ( rev /.00 )

4 0. Crrec nwer: D When he bjec reche ernl peed, he ne rce n zer. Thu he gnude he rce r rcn equl he wegh he bjec. The re whch r rcn de wrk n The bjec hu: W r d rv gv (5.0 kg)(9.8 / )(8 / ).8 kw. Crrec nwer: T 5.0 hrznl vercl T c(5.0 0 µ N T c(5.0 ) 0 N T n(5 ) g N T c(5.0 ) / µ T c(5.0 ) / µ T n(5 g.0 kg 9.8 / 0.5 N ) / µ n(5 ) c(5.0 ) / 0.50 n(5 ) ) g. Crrec nwer: E n v d KE α W E v 90.0 kj 90.0 kj 90.0 kj ( 0.00 )(.00 rd / ) 0 ( 7.00 / ) ( / ). Crrec nwer: C GE gh GE g h nl ye, nl / ( 9.8 / )( 40.0 ) ( KE nl GE nl ) ( KEnl GEnl ) ( KE nl 89.9 kg 9.80 / 0.0 ) ( 50.0 kj 50. kj ) ( KE 75 kj ) ( 50.0 kj 50. kj ) 5 kj E nl ye, nl 50. kj Ne h he GE 0.0 ½ he GE kg 4. Crrec nwer: KE v GE 50.0 kj v g h v 0.6 / 50. kj v 9.80 / 40.0

5 5. Crrec nwer: D ( 5.00 kg)(.50 ) ( 7.00 kg)(.50 ) ( 6.00 kg) ( 5.00 kg) ( 7.00 kg) ( 6.00 kg) 6. Crrec nwer: The blck wll nk unl he wegh he lud dplce equl he wegh he blck. Wegh Wegh lud dplced ( lue) lue 0 kn 400 N ( 0.50 )( 0.50 ) H H Crrec nwer: 8. Crrec nwer: E prn wuld be repelled by he pvely chrged p ple nd rced by he negvely chrged b ple, he elecrc rce n he prn wuld be dwn. Thu, we wn he gnec rce be up. I he prn h velcy n he drecn (b), he rgh hnd rule yeld n upwrd rce. ( qv ) () (d) (b) (c) kω.00 W equvlen equvlen equvlen equvlen equvlen / 0.0 ( " een " by ) : [ 0.0 ( ) 0.0] ( 60.0)( 0.0) kω kω [ ] 50.0 kω equvlen / 50.0 kω kω 9. Crrec nwer: C 5, / nd repreen 5 hl lve. dy 6.4 dy / hl le 5 hl lve 0.0 kω 60.0 kω 0.0 kω

6 0. Crrec nwer: h h 0.50 ( )( ) ( )( 4 ) 4 ( 0 c). Crrec nwer: qe g elecrc Wegh 4 σ (.5 µ C) ( 0.00 kg)( 9.8 / ) ε σ. µ C /. Crrec nwer: D llw ed pn n he wve: cn n /. Crrec nwer: c ( pve pull he negve chrg e upwrd) ( cn n ) J U nt 4 l K (.50 l) 8.4 ( 0 7.5) K 9. kj 4. Crrec nwer: E cld h cld pup kw 7.8 kw h cld 0.0 kw 7.8 kw.6 kw 4.0 C h 0.0 kw -5 C pup cld

7 5. Crrec nwer: C The rce wuld cncel nly r chrge plced he le he.0 µc chrge. q X.0 µc X0-4.0 µc X0 c ( µ C) kq( 4 C) ( 0 ) kq µ 4 ( 0 ) c The rce r he -4.0 C chrge hu Whle he rce r he.0 C chrge ( 4 µ C) kq( C) kq µ 40 0 kq µ C kq µ C 0 0 ( ) ( ).. Thu, he rce cncel.