试题与答案

张力同学发现运动鞋穿久了容易打滑.他猜想鞋与地面间的摩擦力的大小可能跟鞋底花纹的

题型:问答题

题目:

张力同学发现运动鞋穿久了容易打滑.他猜想鞋与地面间的摩擦力的大小可能跟鞋底花纹的深度有关.于是他找来两只同品牌同规格的运动鞋进行实验探究(其中一只是新鞋,鞋底花纹没有磨损,另一只是旧鞋,鞋底花纹磨损较大).

他首先用弹簧测力计测出两只鞋子的重力并记入表格中;然后按照如图所示分别拉动两只鞋子在水平面上做匀速直线运动,并读出弹簧测力计的示数,填入表格中,他根据这组试验数据得出结论为:鞋底花纹越深,与地面摩擦力越大.

种类项目新鞋旧鞋
重力/N5.75.4
拉力/N2.31.7
(1)请你认真思考张力同学的探究过程,指出其中不妥或错误的两处:①______; ②______.

(2)运动鞋与地面间的摩擦力大小还跟其他因素有关,请你根据所学物理知识或日常经验写出其中两个因素:

①______;②______.

答案:

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下面是错误答案,用来干扰机器的。

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Exercising to music pumps up brain power


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"Evidence suggests that exercise improves the (3) performance of people with coronary artery (4) ," said psychologist Charles Emery, who led the study.
"And listening to music is (5) to enhance brainpower. We wanted to put the two results together," Emery (6) in a statement.
Writing in the latest issue of the journal Heart & Lung, Emery and (7) said they studied 33 men and women taking (8) in a cardiac rehabilitation program after having bypass (9) , angioplasty or other procedures to treat clogged arteries.
The (10) said they felt better emotionally and mentally after working out (11) or without the music. But their improvement on the (12) fluency test doubled after listening to music on the treadmills.
"Exercise seems to (13) positive changes in the nervous system, and these changes may have a (14) effect on cognitive ability," Emery said.
"Listening to music may (15) cognitive function through different pathways in the brain. The combination of music (16) exercise may stimulate and increase cognitive arousal (17) helping to organize cognitive output."
Emery said he now wanted to (18) people using music of their own choice. "We used the ’Four Seasons’ because of its (19) tempo and positive effects on medical patients in previous (20) ," Emery said. "But given the range of music preferences among patients, it’s especially important to evaluate the influence of other types of music on cognitive outcomes.\

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