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倾角和摩擦系数的不均匀性对伽利略斜面实验核心结果的影响

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  • 北京师范大学物理学系,北京100875
张润( 1995—) ,男,贵州毕节市人,北京师范大学物理学系2014 级本科生

收稿日期: 2019-08-12

  修回日期: 2019-10-14

  网络出版日期: 2020-05-17

Influence of inhomogeneity of the dip angle and the friction coefficient on the core result of Galileo's inclined plane experiment

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  • Department of Physics,Beijing Normal University,Beijing 100875,China

Received date: 2019-08-12

  Revised date: 2019-10-14

  Online published: 2020-05-17

摘要

伽利略斜面实验的核心结果是小球走过的路程正比于时间的平方,但倾角和摩擦系数的局部不均匀性会导致局部

加速度的不均匀性. 本文用一个简化模型计入倾角和摩擦系数的不均匀性,数值计算发现这些不均匀性不仅引入随机误差,

而且导致路程与时间偏离平方关系. 如果保持倾角情况不变,减小摩擦系数使球从无滑滚动变为有滑滚动,路程与时间对于

平方关系的偏离程度会增大而不是减小.这个结论虽然与直觉相反,但却与物理学史的相关研究得到的结论相符. 为了排除小

球被释放时的随机因素的影响,本文在实验中设计了零初速度释放小球的装置,还设计了一个更方便的测量摩擦系数的方法.

本文引用格式

张润, 张杨瑜莹, 熊刚 . 倾角和摩擦系数的不均匀性对伽利略斜面实验核心结果的影响[J]. 大学物理, 2020 , 39(05) : 58 -61 . DOI: 10.16854 /j.cnki.1000-0712.190368

Abstract

The core result of Galileo's inclined plane experiment is the proportion relation between distance and

the square of time,but the local inhomogeneity of the dip angle and friction coefficient leads to inhomogeneity of local

acceleration. In this paper,a simplified model including inhomogeneity of the dip angle and friction coefficient

is introduced. Numerical results show that this inhomogeneity not only induces random error but also leads to deviation

of the square relation between the distance and the time. It is further found that if the dip angle keeps unchanged

and the friction coefficient decreases,the ball should change from non-slip rolling to slip rolling,the deviation

degree of the square relation between the distance and the time would increase rather than decrease. This result,

although contrary to intuition,coincides with the result achieved in some corresponding researches on the history

of physics. These theoretical results are confirmed by our experiments. In order to exclude the random factors in

releasing the ball,an equipment is designed to release the ball with zero velocity. A more convenient method is also

carried out to measure the friction coefficient.

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