1、 ( 12 4 48 7-12 , 4 2 0 ) 1 M m P A ( )( ) A 2mg B 2mg C 3mg D 3mg C v R A A 2 m A g/2 H B h C A C ( ) A B C mg(H h) D mg(H h) D A C 3 AB R O AO AO BO A R B cos R C cot R D tan R A B A AB A 4 m h A 2mg ghB mg ghC 1 2 mg ghD 1 3 mg gh B h v mgH=mgh+ 2 1mv 2 mgh= 2 1mv 2 mgH=2 2 1mv 2 v= gH P=Fv=mgv=m
2、g gH B P= t W P=Fv 5 P Q A PQ tt B : 2 :1 PQ EE C : 2 :1 PQ qq D : 4 :1 KP KQ EE C 6 m L a m/2 b) m/2 c) a v a b) v b c) v c ( ) A v a v b v cB v a v b v c C v a v b v cD v a v c v b D 7 AB AB A AB AB BC A B B B C D B B AB B B 8 m C A B v 1 F v 2 (v 2 v 1 y ) ( ) A F m g B F m g C F y F m g D F y F m g BD 9 1 v 1 a 2 v 2 a 3 v 3 a 6 ( ) A 3 2 v v = 1 7B 3 1 v v = 7 1C 3 2 1 7 1 a aD 49 1 3 2 a a BC a=r 2 2 r GMm = r mv 2 =ma 10 v 1 , v 2 , v 2 m 2 m 1 A m 2 m 1 O B (1) m 2 s (2) m 1 R/2 2 1 m m= (1)R (2)
