试题与答案

在探究“滑动摩擦力的大小与哪些因素有关”的活动中.(6分) ⑴在水平桌面上,用

题型:实验题

题目:

在探究“滑动摩擦力的大小与哪些因素有关”的活动中.(6分)

⑴在水平桌面上,用弹簧测力计沿水平向左拉动木块,使其做             运动,弹簧测力计示数如图所示.则木块所受的滑动摩擦力为_______N.当弹簧测力计的示数增大为4N时,木块作加速运动,此时该物体受到的摩擦力为_______N。

⑵小华准备探究接触面积对滑动摩擦力的影响,他将木块沿竖直方向截去一半后,测得木块所受的滑动摩擦力变为原来的一半.他由此得出:滑动摩擦力的大小随接触面积的减小而减小.你认为他的探究过程中存在的问题是:         

⑶小华家正在装饰新房,在购买瓷砖时,选中了其他方面都满意的两种品牌的瓷砖,小华想从中选择防滑性能好的,请你设计一个简单的实验,帮助小华挑选瓷砖。简述实验方法:

                                                                       

                                                                     

答案:

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参考答案:B

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题型:完形填空

阅读下面短文,用括号内所给动词的适当形式填空

I am John.I am l7 years old,and I live in England.My father works in a horse-riding school.I have been riding since I(61) _____ (be)six.I go horse-riding every Saturday.Now, I can ride quite well.I often(62) _____ (spend)all Saturdays at the riding sch001.I help to get the horses ready.I also help the new students.

Look,there are some people(63) _____ (train)horse-ridin9.The girl named Xinyi (64) _____ (walk)the horse around(遛马)and getting ready to get onto the horse.She is from China.She looks beautiful.She(65) _____ (study)here three times.Last time,I helped her move up and down at the same time as the horse(随着马动的频率).while we were learning how to jump the horse,suddenly she fell off the horse and(66)_____(hurt)her knees badly.I felt sorry that I(67)_____(not help)her at that time.I thought she wouldn’t come this Saturday.To my surprise。she came again! What a brave girl! Last month,she(68) ____ (invite)to come to England for a fashion show.She said she was glad to have the chance to come here and she enjoyed herself.

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“I hope(70) _____ (meet)you soon.”

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