题干

在课外兴趣小组活动中,小明想验证重力势能与高度的关系:他在水平地面上铺一张纸,将蓝球表面涂黑,使蓝球分别从不同高度处自由下落,在纸上留下黑色圆斑A、B,如图所示。球从较高处下落形成的圆斑是图中____ (选填“A”或“B”),你判断的依据是____ 。
爱动脑筋的小明发现,篮球落地后反弹的高度每次也不相同,那么篮球由静止开始下落,反弹的高度究竟与哪些因素有关呢?小明与大家一起对这个问题进行了讨论,提出了不同的猜想。
猜想1:篮球反弹的高度可能与球的型号有关;       
猜想2:篮球反弹的高度可能与下落的高度有关;   
猜想3:篮球反弹的高度可能与地面材料有关。
于是,小明用两只充足气的#7(标准男子)、#6(标准女子)篮球及刻度尺,在水泥地面和木制地板上进行了实验。通过实验,得到的实验数据如下表:

(1)要验证猜想2,需要选用实验序号为____ 、____ 的两组数据进行分析。
(2)通过他的实验数据,可得到的结论是:篮球反弹的高度与____ 有关,与
____ 无关。

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答案(点此获取答案解析)

B,\u8d28\u91cf\u4e00\u5b9a\u65f6\uff0c\u7269\u4f53\u4e3e\u5f97\u8d8a\u9ad8\uff0c\u5177\u6709\u7684\u91cd\u529b\u52bf\u80fd\u8d8a\u5927\uff0c\u5230\u8fbe\u5730\u9762\u65f6\uff0c\u5f62\u53d8\u4e5f\u5927,2,\u4e0b\u843d\u7684\u9ad8\u5ea6\u3001,\u573

同类题4

阅读理解

    Rosie Dutton, a teacher from Relax Kids in Tamworth, UK, used two apples to show her students the often unseen but harmful effects of school bullying(校园欺凌). She posted the lesson on Facebook, where it's been shared more than 160,000 times.

    Rosie Dutton explained that during one of her classes she presented the children with two red apples. What the kids didn't know was that before the lesson, she had repeatedly dropped one of the apples on the floor. And yet, on the outside at least, both apples looked perfect.

    “I picked up the apple I'd dropped on the floor and started to tell the children how I disliked this apple,” Dutton wrote. “I told them that because I didn't like it, I didn't want them to like it either, so they should call it names too.”Some of the children looked at her as if she were “crazy”, but the students passed the apple around the circle, calling it names.

    Continuing the exercise, the teacher then passed the second apple around the circle. This apple, however, was showered with words like: “Your skin is beautiful,” and “ what a beautiful colour you have.”

    Dutton then showed the students both apples once again, stressing that “there was no change, and both apples still looked the same.”

    Finally, Dutton cut both apples open. The apple that the class treated kindly looked fresh inside. But the other apple—the one they'd treated poorly —was bruised(瘀伤的) beneath its skin.

    “I think there was a light bulb moment for the children immediately,” Dutton said. “When people are bullied, especially children, they feel horrible inside and sometimes don't show or tell others how they are feeling. If we hadn't have cut that apple open, we would never have known how much pain we had caused it.”

    Dutton explained how important it is to teach children to stand up for one another, and to stop any form of bullying.

    “Let's create a generation of kind caring children,” the teacher wrote. “The tongue has no bones, but is strong enough to break a heart. So be careful with your words.”