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解题的意义毋庸置疑,解题的方法大有研究。解题指导有三忌:一忌贪多求难;二忌故弄玄虚;三忌规定模式。对此,本文不想赘述。现结合个人教学体会,就如何教会学生解题,谈一些认识。一,引导学生过好审题关。了解题设物理过程,明确已知量和待求量,这是审题的一般常识。值得注意的是,有些初看起来似乎无关紧要的字、词、句,往往暗示着某个条件、某个过程、某种联系或某种规律,忽视它或不理解它,就会“束手无策”;反之,分析它,揭示它,就会“茅塞顿开”。〔例〕图(1)所示电路:当通以220伏、50赫兹交流电时,三个相同的灯一样亮。若改用220赫兹交流电(电压不变)时,则(1)三个灯的亮度如何变化:(2)若R=50欧,则L、C的值是多少? 一些同学在各第一问时很顺利,解第二问就犯嘀咕了:其一,不知道通过什么关系求解L、C_1其二,想到X_L=2πfl,X_O=1/2πfC,但不知道X_L、X_C
Undoubtedly the meaning of problem solving, a great deal of solution to the problem. Problem-solving guidance has three bogey: a bogey more difficulty; two bogey get rid of the mystery; three bogey provisions mode. In this regard, this article does not want to go into details. Now combined with personal teaching experience, on how to teach students to solve problems, talk about some understanding. First, guide students to a good examination of the subject. Understand the problem of physical process, a clear amount of knowledge and to be sought, this is the general knowledge of the trial. It is noteworthy that some words, phrases and sentences that at first seem seemingly insignificant often imply a certain condition, process, connection or some kind of law. If we ignore it or do not understand it, we will be “at a loss” ; On the contrary, analyze it, reveal it, it will “open the door.” [Example] The circuit shown in Figure (1): Three identical lamps lit up at 220 V, 50 Hz AC. If the switch to 220 Hz AC (constant voltage), then (1) how the brightness of the three lights change: (2) If R = 50 Europe, the L, C value is how much? Some students in the first question When it is very smooth, the solution to the second question on the guilty whispered: First, do not know what the relationship between the solution L, C_1 Second, think of X_L = 2πfl, X_O = 1 / 2πfC, but do not know X_L, X_C