1、13 20225 832430 1C 2D 3A 4A 5B 6C 7D 8C 4416420 9AD 10BC 11AB 12BCD 660 1AC220.48232 141b2 2D13 37N2 157 1aAB=C=45150aAB=301 1 1 2bABaAB bBC =75 bsin sinC1 bBCbAC bs1 s=96l 2s x=3snc1 2 33ltc 1 169 1Omgsin =Ff1 aO 1 aO1 1 R E S A V + + A B C D a b 23 A1 kmFma=1 =4mag1 x1kx1mgsin +Ff1A21 ad=2(A1-A2)=
2、1 1714 F 2mgsin2mgcos2ma 1 2mg F=2ma 1 F= a= 1 fmg f=ma 1F= 21mfmgma 1 12mmgfFma 1 122cos2sin2Fmgmgma1 134ga 1 212aL 21212a H 1 1 1 1112xhHH2212aH 22222a H 1 133 1 18.1abB2a Fmgma 1 28m/sa AA 1 R 1 B1MM 1 2B2114m/sat B2abB2B1=0B24m/s abcd122mm 2 22m/s 1 0.2m0.5mhrPPB2 B23 23222B iLtmm 2 23222B qLmm 222B LdqR 1 31.375m/s0B2 1 1 AA 1 3abAA211(2 )2JQIR t 1 B2 1 Q=Q1+Q2=2.42J 1
