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一、不等臂天平的测量误差应用物理天平测物体的质量,一般将待称物体放在天平左盘,将砝码放在右盘。待天平平衡后,左盘物体的质量即等于右盘砝码的克数。这种测量方法通常称为单称法(为讨论方便起见,本文只研究中学常用的普通天平,并且不考虑游码的作用)。但事实上,一般天平的两个横梁多少有些差别,天平一盘中砝码的质量并不完全与另一盘中物体的质量相等。此时如果仍用单称法,则会给测量带来误差。设天平横梁左右两臂长度分别为 L_1、L_2,待测物体质量为 m;当待测物体放在左盘时,右盘须加质量为 m_1的砝码,才能使天平平衡。依据力矩平衡原理,天平平衡时有:
First, ranging from arm balance measurement error Physical balance test the quality of objects, generally the object to be weighed on the balance of the left disc, the weight on the right disc. Balance until after the balance, the quality of the left disc is equal to the weight of the right disc grams. This method of measurement is often referred to as the simplex method (for the sake of discussion, this article only studies the ordinary common in middle school, and does not consider the role of the code). However, in fact, the balance of the two beams somewhat different, the weight of a balance weight is not exactly the same quality as the other plate. At this point if you still use the single name method, it will give measurement error. Assuming that the length of the left and right arms of the horizontal beam are L_1 and L_2, respectively, the mass of the object to be measured is m; when the object to be measured is placed on the left disk, the weight of the right disk must be added with mass m_1 to balance the balance. According to the principle of moment balance, balance balance are: