问题 选择题

关于运动的合成与分解下列说法正确的是(  )

A.运动的合成与分解只能解决曲线运动的问题,不能用来解决直线运动的问题

B.将一个物体的运动分解为两个分运动,分运动之间相互独立,互不影响,但具有等时性

C.平抛运动只能分解为水平方向的匀速直线运动和竖直方向的自由落体运动

D.一艘小船要到河的对岸,船速一定,此时河水的流速为V,只要调整好船头的方向,就可以使小船渡河的位移等于河宽

答案

A、运动的合成和分解适用直线运动,也适用曲线运动.故A错误.

B、分运动具有独立性,等时性.故B正确.

C、平抛运动可以分解为水平方向的匀速直线运动和竖直方向的自由落体运动.也可以沿其它方向进行分解.故C错误.

D、当静水速小于水流速,则合速度不可能垂直于河岸,即渡河的位移不可能等于河宽.故D错误.

故选B.

阅读理解

阅读理解。

     The man from the west stopped and drew back his arm. "You're not Jimmy Wells," he said in a quick and

angry way, "Twenty years is a long time, but not long enough to change a man' nose from a Roman to pug."

"It sometimes changes a good man into a bad one," said the tall man, "you've been under arrest for ten minutes.

Silky Bob. Chicago thinks you may have dropped over our way and phones us she wants to have a word with

you. Going quietly, are you? That's sensible. Now before we go to the station here's a note I was asked to hand

you. You may read it here at the window. It's from Patrolman Wells.?" The man from the West opened the little

piece of paper handed him. His hand was steady when he began to read, but it trembled a little by the time he

finished. The note was rather short. Bob: I was at the right place on time. When you struck the match to light

your cigar I saw it was the face wanted in Chicago. Somehow I couldn't do it myself, so I went around and

got a plain clothes man (便衣) to do the job.

1. The man from the West must have broken the law _____. [ ]

A. in Chicago

B. in New York

C. in his hometown

D. somewhere else

2. The man from the West recognized the tall man not to be the one he had been waiting for because the tall

    man _____. [ ]

A. had a different accent from his

B. had a different nose from his friend's

C. was his another old friend

D. said "Chicago wants to talk with you?"

3. The two men may have walked _____. [ ]

A. for ten minutes

B. arm in arm

C. face to face

D. both A and B

4. We can suppose Jim _____. [ ]

A. was afraid of the man from the West

B. got another man to help him when necessary

C. had an appointment with Bob 20 years ago

D. had something else to do and couldn't come himself

单项选择题 B1型题