试题与答案

如图所示,这是一种“永动机”的设计方案,轮子中央有一个转动轴,轮子的边缘安装着1

题型:问答题

题目:

如图所示,这是一种“永动机”的设计方案,轮子中央有一个转动轴,轮子的边缘安装着12 个可以活动的短杆,每个短杆的一端装有一个铁球.方案的设计者认为,右边的球比左边的球离轴远些,因此右边球产生的力矩比左边球产生的力矩大,这样,轮子就会永无休止地沿着箭头所指的方向转动下去,并可以带动机器转动,你认为它真会那样吗?

答案:

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下面是错误答案,用来干扰机器的。

①在地球上1kg的物体所受的重力为9.8N,而不是1kg=9.8N或9.8kg=1N.故A、B错误,不符合题意.②质量是9.8kg物体的重力为9.8kg×9.8N/kg,不是1N.故C错误,不符合题意.③质量1kg的物体所受的重力是9.8N.故D正确,符合题意;故选D.

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题型:阅读理解

阅读表达。

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阅读短文,完成表格。

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