1、 20 11 120 1 00 1 2 4 48 2B 1. m L 3m L 30 A B 1 2 mg C 3 2 mg D mg 2. A B C D 3 O ON N MO M N M O v s a EK M N O t v A O t s B O t a C O t E k D 3m 30 0M N o A B 4. 0.8s 0.2s A 10 B 8 C 5 D 2 5.1930 00km 2006 8 24 6 (IAU) G A B C ( n) D ( n) 6. x a A x 5m /s B x 5m /s C x 1m /s D x 1m /s 7 AB AB A
2、B A B EA EB B A A B A B B A C EAEB D EA = EB 8. U I R E r A B (1 Ir E)x100% C I 2 r D U 2 R9 MN PQ ab cd t=0 B t ab cd ab cd A 0 t 0 B t0 t C 0 t 0 t/s y/cm 0 4 x/m 0 a y/cm 5 1 2 3 D t0 t 10. m +q L O O A A B C E =mgtan /q D 11. X X uX t Y Y uy t 12. abcd ab 1 l bc 2 l m R M ef ef T 3T O t u y2T u
3、x O 2T T 3T t X Y X Y X Y X Y A B C D - - + - + + - x x y y B B ab A 2 ) sin ( l mg Mg B sin Mg mg m C 22 1 ( sin ) Bl Mg mg R D 1 ) sin ( Bl R mg Mg 8 , 72 1 2 13. 6 m A1 A 1 A2 t A1 A 2 s a = A1 A 2 h F = 14. 4 B n L m A m x0 B I x C B x x0 I L m n g 15.(8 ) 1.5V 1.5V 0 .3A 3m A 1.5V 3 K 1 2 A(0 3
4、0 ) B(0 3 k ) _ 3 U -I E V r = _ 16 8 m , +q 1 F 2 E 17. 10 h =20m 0=10m s g s 2 1 t vt ( ) 2 a=2.5m s2 x vt 18. 10 R = 0.10 m M = 480g m = 20g vo= 100m/s g /s 2 (1) v (2) N (3) R X 19 12 R r B m r/2 v1 v2 Bo r/2 a Q 20. 14 x oy x L= 0.30m B 0 = 3.75 10 -4 T U = 4.5 10 3 V y e 1.6 10 -19 C m 9.0 10 -31Kg l v 2 x 0 x 4L 3 x 0 x NL(N O L 2L 3L 4L 5L y x B O L 2L 3L 4L 5L x B 0 -B 0
