1、 - 1 - 02 1. m=3kg A B A k=l00N/m B F a= 2m/s 2 A g=l0m/s 2 (1) A B F (2) A B 2. 3-7 A B mA mB k , C F A B C A a A d g - 2 - 3. 3-8 A B v1=30m/s 100m 2m s=200m v2=10m/s 70% B 30% A. A m1=2000kg B m2=6000kg g=10m/s 2 . - 3 - 2-10 1 A B 2-10 2 a v22 v22 = 2as 1 F F m1+m2 gsin = m1+m2 a 2 -2 3 f f= 30
2、100 F 4 FN f FN m1gsin =m1a 5 2 4 5 FN= 30 100 m1+m2 a+gsin m1 a+gsin 6 1 3 6 FN=880N 3. A A B C B F B A B C 3-9 A B C m g F - 4 - . T A B C a C xian3 A B C F=3ma 1 B F-T=ma 2 C T 3 Tsin 4 1 2 T=2ma 5 3 4 T 2 =m 2 a 2 +g 2 6 5 6 a= 3 3 g 1 7 F= 3mg - 5 - 4 13 A B mA 10kg mB 5kg A B 1 2 A B 0.2 3 A B
3、 A 0. 2 B 0.8 - 6 - (1) 6m/s 26m/s 20 (2) 4.4m/s 24.4m/s 20 (3) 4.4m/s 20m/s 20 2 a m m g m m g m m B A B A B A ) ( cos sin 2 / 4 . 4 cos sin s m g g a A B m g m g F m a B B B T B sin cos 0 T F 4 3 B cos sin g m g m B B B B A F T 0 2 / 4 . 4 ) cos (sin s m g a A A 5 - 7 - A A A A A T A a m g m F g m cos sin B B B B B T B a m g m F g m cos sin F T 0 g a a A B B A cos ( ) B A 3 3 m 2 A 60 cos 60 sin a m g m T A A 2 B 30 cos 30 sin ma T mg 2 mA= a g ma mg 3 3 1 0 3 3 m 1
