问题 问答题

物体A的质量为m(kg),原静止在光滑水平地面上的O点,先受到一水平向右的恒力F(N)的作用.经时间t(s)后撤去F,立即改用水平向左的恒力2F(N)作用2t(s).求:

(1)物体向右运动的最大位移为多少?

(2)在2F作用2t(s)末,该物体距O点多远?

答案

(1)     (2)

阅读理解

If parents bring up a child with the aim of turning the child into a genius(天才), they will cause great damage to him. According to several leading educational experts, this is one of the biggest mistakes that some parents make. Generally, the child will understand very well what the parents expect, and will fall. Unrealistic expectations of the parents can cause great damage to children.

However, if parents are realistic about what they expect their children to do, and are hopeful in a sensible(明智的) way, the child may succeed -especially if the parents are very supportive to their children.

Michael Li is very lucky. He is very fond of music and his parents help him a lot by taking him to concerts and let him attend piano and violin lessons. Although his father is a good musician, he never makes Michael enter music competitions if he is unwilling to.

Michael’s friend, Winston Chen, however, is not so lucky. Both his parents are successful musicians, and they set too high a goal for Winston. They want their son to be as successful as they are and so they enter him for every piano competition held. They are very unhappy when he does not win. “When I was your age, I used to win every competition I entered.” Winston’s father tells him. Winston is always afraid that he will disappoint his parents and now he is always quiet and unhappy.

小题1:This passage is mainly about_______.

A.how parents should bring up their children

B.what aim can be easier for a child to achieve

C.how parents should make a child a musician

D.what differences there are between parents小题2:Michael is fortunate because_______.

A.his parents help him in a practical way

B.he was born in a rich family

C.his father is a successful musician

D.he can do anything he likes小题3:Winston’s parents set so high a goal for him that_______.

A.he has to do his best to do everything

B.he has made greater progress in music

C.he is afraid he may disappoint them

D.he wants to be a great musician someday

多项选择题