（通用版）2018高考物理一轮复习 第1章 运动的描述 匀变速直线运动的研究 第3节 运动图象、追及和相遇问题教师用书.doc

1、 1 3 1 1 x t (1) (2) x t x t x t (3)x t 2 v t (1) (2) v t v t v t . (3)v t 2 2 1 (1) (2) 2 (1) (2) 1 (1) x t v t (2)x t v t (3)x t (4) v t (5) x t (6) (7) 2. x t x t 6 s ( ) A 0 m B 2 m C 4 m D 12 m D x t 2 s 2 m 2 3 s 4 m 2 6 s 4 m 8 m 6 s 12 m D 3 ( ) 92492031 A 1 B 2 C 2 D 3 5 D 1 A 2 B 2 C 3 5 D

2、 4 v0. a 2a x ( ) 92492032 A x B 3 2 x C 2x D 5 2 x 4 B v 2 0 2ax v 2 0 ax2 x2 x 2 x 2 v0t v0 v0 a v 2 0 a 2x x x2 x 2 x x 2 2x x 3 2 x B x t v t t x t v 1 (x t) ( ) 92492033 A t1 B t2 C t2 D t3 C x t t1 A t2 5 B t2 C t3 D 2 ) v t ( ) A 6 s 10 m B 0 2 s 4 6 s C 2 4 s D 2 4 s C 0 2 s 4 6 s 0 6 s 2 4

3、s 10 m A 0 2 s 4 6 s B 2 4 s C 2 4 s D 1 x t v t x v t 2 x t v t x t v t 3 x t v t 1. 6 2 1 1 ) a v s. t 0 ( ) 92492034 C A 1 s A B 2 s 2 4 s B C 1 s 2 s 2 s 0 C D 1 s 1 3 s 2 s 0 3 s D 2 (201 ) v x ( ) 92492035 A E x v mgx 1 2 mv 2 E x v 2 2g E mg 7 ( E mg 0) A 2 3 ) v t ( ) 92492036 C 0 1 s a1 1 m

4、/s 2 1 s v1 a1t 1 m/s 1 2 s a2 1 m/s 2 2 s v2 v1 a2t 0,2 3 s 0 1 s 3 4 s 1 2 s C 1 2 3 1 (1) (2) 2 A B x0 (1)A B xA xB x0 vA vB. 8 (2) xA xB x0 vA vB. (3) vA vB xA xB x0 vA vB. 3 (1) (2) t t 0 0 0 (3) v 16 m/s a 2 m/s 2 v 4 m/s a 1 m/s 2 (1) (2) (1) (2) (1) v t v t v t v a t1 v t v a t1 t1 v v a a 4

5、 s x x x v t1 1 2 a t 2 1 v t1 1 2 a t 2 1 (v v )t1 1 2 (a a )t 2 1 24 m. (2) v t2 1 2 a t 2 2 v t2 1 2 a t 2 2 12t2 3 2 t 2 2 0 9 t2 8 s t 2 0( ) (1) x x x v t 1 2 a t 2 v t 1 2 a t 2 (v v )t 1 2 (a a )t 2 12t 3 2 t 2 3 2 (t 4) 2 16 t 4 s xm 24 m. (2) x 12t 3 2 t 2 0 t2 8 s t 2 0( ) (1)24 m (2)8 s

6、1 1 ) 6.0 m/s 25 m 1.0 m/s 2 ( ) 92492037 A 36 m B 7 m C 43 m D B 25 m 1.0 m/s 2 6.0 m/s 6.0 m/s t 6 s 36 m 18 m 18 m 25 m 36 m 7 m A C B D 2 2 )A B A vA 10 m/s B vB 30 m/s B A x0 85 m A B B 180 m B A 10 B 92492038 B aB v 2 v 2 0 2ax 0 2 30 2 2( aB aB 2.5 m/s 2 t vBt 1 2 aBt 2 x0 vAt 30t 1 2 t 2 85

7、10t t 2 16t 68 0 16 2 0 t vA vB aBt1 t1 8 s xB vBt1 1 2 aBt 2 1 160 m xA vAt1 80 m x x0 xA xB 5 m. 5 m 3 3 A B s 7 m A vA 4 m/s B vB 10 m/s a 2 m/s 2 A B ( ) A 7 s B 8 s C 9 s D 10 s B t 5 s B xB 1 2 at 2 25 m A xA vAt 20 m A B s s xB xA 7 m 25 m 20 m 12 m t s vA 3 s A B A B 5 s 3 s 8 s B 4 11 4 40.

8、5 m v1 16 m/s a1 2 m/s 2 v2 4 m/s a2 1 m/s 2 (1) (2) . 92492039 (1) t1 v1 a1t1 v2 a2t1 16 2t1 4 t1 t1 4 s x1 v1t1 1 2 a1t 2 1 48 m x2 v2t1 1 2 a2t 2 1 24 m xmax x0 x1 x2 64.5 m. (2) t2 v1 a1 8 s x1 v1 2 t2 64 m x2 v2t2 1 2 a2t 2 2 64 m x 40.5 m v2 v2 a2t2 12 m/s x v2 t3 1 2 a2t 2 3 40.5 12t3 1 2 t 2 3 t3 3 s t t2 t3 11 s. (1)64.5 m (2)11 s 1 2