问题 问答题

如图是探究动能大小与哪些因素有关的实验,铜球、铝球体积相同且实心.

(1)实验中你通过观察 ______知道动能的大小.

(2)实验中采用 ______方法,使得铜球和铝球到水平面的速度相同.

(3)根据图甲和乙,探究的问题是 ______.

(4)根据图甲和丙,得到的结论是 ______.

答案

(1)通过观察球把纸盒推出距离的远近判断球的动能大小,这是一种转换的方法;

(2)球的高度在题中代表了速度的大小,因此要保证到达底端时的速度相等,必须让它们所处的高度相同;

(3)由甲乙两图可知,两球的所处的高度相同,但两球的质量不同,所以可以探究动能的大小与质量的关系;

(4)甲丙两图中的球的质量相同,所处高度越高的球,把纸盒推出的距离越远,因此可以得出的结论是:在质量一定时,速度越大,动能越大;

故答案为:纸盒被推的远近;高度相同;动能大小与质量的关系;质量相同时,速度越大,动能越大.

选择题
写作题

阅读下面的短文,然后按照要求写一篇150词左右的英语短文。

     As we all know, life is full of dreams and having a good dream is of great importance in our daily life.

Without a good dream, people can't make progress; without a good dream, countries can't develop;

without a good dream, the world can't become so beautiful! And I hold the strong belief that everyone,

whether he is old or young, poor or rich, junior or senior, does have a good dream! After all, dreaming

is certainly a positive part of our life, and wishing for good things, however, costs nothing!

     What's more, it is important to fly our dreams, especially for those who are Senior 3 students. It is

high time for them to fly their dreams. If they can't let out dreams fly, the dream would just be a dream,

not reality!

     Therefore, it is no wonder that so many people have a dream since their childhood. With a nice

dream, China succeeded in hosting the 29th Olympic Games in 2008; with a nice dream, Hong Kong

returned to the motherland peacefully in 1997; with a nice dream, Yuan Longping rids the world of

hunger; with a nice dream, Michael Jordon becomes the most popular basketball star; with a nice

dream, I can stand on this stage to compete in the final English speech contest. And with an aim of

achieving success, I must do the best!

     So my good friends, if you want to realize your dream, please do not be afraid in face of difficulties

or give up in face of failure nor lose your dream in face of pains. You must keep going forward bravely!

Just fly your dream highly above the sky!

[写作内容]

1. 阅读短文后用30词左右概括短文的要点。

2. 以“放飞梦想”为主题,以120词左右发表自己的看法,并包括以下内容要点:

(1)列举自己或现实生活中中学生梦想成真的一件事;

(2)结合自己的实际,谈谈你现在的梦想,并说明打算如何实现。

[写作要求]

1. 在作文中可以使用亲身经历或虚构的故事,也可以参照阅读材料的内容,但不得直接引用原文中的句子;

2. 作文中不能出现真实姓名和学校名称。

[评分标准]

概括准确,语言规范,内容合适,篇章连贯。