问题 计算题

(16分)篮球运动是一项同学们喜欢的体育运动,若测得某个篮球从开始下落到触地反弹至最高点过程中的v-t图象(向下为正方向),如图所示.若篮球的质量为m=0.6kg,g取10m/s2.求触地过程中篮球对地面的平均作用力(不计空气阻力).

答案

篮球对地面的作用力也为39N,方向竖直向下

以向下为正方向

                 …………12分

代入数据                                 …………2分

由牛顿第三定律可知,篮球对地面的作用力也为39N,方向竖直向下……2分

判断题
单项选择题

Just how does a person arrive at an idea of the kind of person that he is He develops this (1) of self through a gradual and complicated (2) which continues throughout life. The notion is an (3) that one establishes only with the help of others. (4) the elementary knowledge that one is short or tall is a comparative judgment that we cannot make (5) we have the opportunity to (6) ourselves with others. One’s idea of qualities which are harder to (7) is even more dependent upon other people’s ideas.

Whether one is intelligent, or stupid; attractive, or ugly; these and many other ideas of the self are (8) from the reactions of people with whom we (9) This process of (10) the nature of the self from the reaction of others has been labeled the "Looking-glass Self" by Cooley, who carefully analyzed this psychological (11) of self-discovery.

Just as the picture in the mirror gives an image of the physical self, (12) the perception of the reactions of others gives an image of the social self. We know, (13) , that we are good at certain things and not at others. This (14) came to us from the reactions of other persons, first our parents and then other individuals (15) in life. It should be remembered that, as other people’s reactions could be (16) and understood in more than one way, the looking-glass self with which the individual (17) may easily differ from the image others have actually formed of his (18) Clearly, it is our perception of the responses of others and not their (19) responses that (20) our self-image, and these perceptions are often not accurate.

12()

A.while

B.for

C.so

D.since