解答计算题书写应规范化

对于物理计算题,高考试题中明确提出了书写规范化的要求:"解答应写出必要的文字说明、方程式和重要演算步骤.只写出最后答案的不能得分.有数值计算的题,答案中必须写出数值和单位."但是在评卷过程中发现不少考生的答案步骤不全、条理不清、符号混淆、书写零乱、遗漏单位等.这不仅给评卷工作造成困难,而且直接影响考生的考试成绩.     

对一道清华自招考试题的巧解

近几年在高考题中出现了高中生无法计算,只能靠综合分析判断得出答案的选择题.解答这类题只能通过临界条件、边界条件、赋值分析、极限分析、单位验证等方法判断其合理性来确定答案.如下面2道例题.     

用Excel解决高中物理中的复杂问题

高中学生具有强烈的求知欲,迫切希望了解一些复杂的物理问题的答案以及答案是如何求出的.给出用Excel解决高中物理中的复杂问题的示例和基本步骤,总结让学生用Excel解决高中物理中的复杂问题的意义.     

对2010年一道高考答案的质疑及分析

2010年普通高等学校招生全国统一考试(理综)全国卷Ⅰ中选择题的21题答案给的是B、C.但笔者认为这个答案有些问题.原题如下.【题目】一简谐振子沿x轴振动,平衡位置在坐     

一个出人意料的实验结论

这是最近我在一个物理实验中得到的结论.因为有一类物理习题的答案和对答案的解释与这个实验结论不统一,我们必须重新讨论、认识这个问题.那么,这是一个什么样的结论呢?     

从一道高考题谈多普勒效应

2001年高考上海卷第13题是一道联系社会生活实际的好题,它涉及到用现代科技进行交通监测.该题本应只有一个答案,而评分标准中提供了两个答案(17 m/s,17.9 m/s),这究竟是怎么回事呢?     

物理教学中要体现学生的主体作用

本文结合“法拉第电磁感应定律”的教学过程,介绍一下我们在“物理课堂教学中,如何发挥学生主体作用”这一研究课题中的一点尝试. 1 指导预习,培养兴趣,提高课堂效益发现问题,产生疑问,进而寻求答案,这可以说是人类的天性.在教学过程中,如何充分调动学生这种本能的求知欲望呢?组织有计划、有指导的课前预习是一个有效的手段.因为与其在教学中反复强调重点和难点,倒不如让学生们通过预习,自己去发现重点和难点,并主动地通过课堂教学过程去寻找答案.变我教你学为我和你一起去寻找答案.这里的关键是:使学生明确预习的目的是重在发现问     

吹肥皂泡过程中做功问题的讨论

现有的普通物理热学教材中,一般都有这样一道典型题:"将压强为p0=1.0 atm的空气等温地压缩进肥皂泡内,最后吹成R=2.5 cm的肥皂泡.设肥皂泡的胀大过程是等温的,求吹成这个肥皂泡所需做的总功,设肥皂水的表面张力系数σ=4.5×10-2N/m".有些教材[1～3]将其做为例题,而另一些教材[4～5]则做为习题.做为例题的教材中的分析求解过程一样,答案也一样;而做为习题的教材中,有的附有答案[4],答案与前者完全相同.笔者认为,这些教材中分析求解的方法及结果值得商榷.     

与参考答案不一样的正确答案——由非独立变量引发的问题

2021年上海青浦区的物理二模卷最后一题的最后一问,有学生给出了和参考答案看上去很不一样的另外一个答案.进一步的计算可以证明两个答案都是正确的.之所以出现这种情况,是因为题目中给出的物理量不是独立变量.这也给物理教师提出了更高的要求:在命题和阅卷过程中,应注意这一问题.在注重物理核心素养培养的今天,当学生提出质疑,应认...     

1987年全国中学教师《专业合格证书》文化专业知识考试高中物理教师力学试题

注意: 1.全卷共八个大题. 2.第二、四、五、六、七题要求写出必要的文字说明、方程式和重要演算步骤.只写出最后答案,而未写出主要演算过程的,不能得分.有数值计算的题,答案中必须明确写出数值和单位. 一、(24分)本题中每小题给出的几个说法中只有一个是正确的.把正确的说法选出来,并将正确说法前的字母填写在题后方括号内.每小题,选对的,得3分;选错的,得0分;选两个或两个以上答案的,得0分.字母填写在方括号外的也不得分. 1.一物体从某一确定高度以v0的速度水平抛出.已知它落地时的速度为vt,那么它的运动时间是 2.将两物体a和b分别以初速度v…     

关于"太阳在银河系中所受引力与到银心距离r的关系"的讨论

讨论了银道面内的引力场强分布和太阳在银河系中所受引力与到银心距离r的关系，指出引力场强g并不是与r的平方成反比，这是由于银河系的大小和形状不能忽略造成的．强调了万有引力定律的适用条件．     

On the calculation of the bremsstrahlung in the region of the plasma frequency

On the basis of the classical theory of radiation produced in incomplete Coulomb interaction, a formula is derived for the coefficient of the bremsstrahlung of fully ionized plasma. In the region of rectilinear approximation a comparison is made with the results of the quantum formula derived from the Born approximation. Furthermore, the influence of dispersion upon the emission coefficient is taken into account; some relations for the region of dispersion are given.     

Dependence of the Intensity of the Spectral Lines and the Composition of the Sample and the Plasma Parameters of the Unipolar Arc

The investigation was made of the dependence of the intensity of Tl, Ga, Mo, Mg, Mn, Sn, Bi, Ni, Zn, Pt and Au spectral lines and the plasma parameters (temperature T, electron concentration n_e, degree of 6 ionnization α) from concentration of lithium additive.     

On the predictability of the positions of the convergence zones in the ocean

The disagreement between the experimental and calculated positions of the first convergence zone are known from many publications. The most probable cause for such a disagreement, namely, the incorrect specification of the input data for the calculations, is considered. The lack of simultaneity between the hydrological surveys of the region and the acoustic experiments is emphasized. The experimental data obtained by the author in five ocean regions are presented. These data characterize the diurnal variability of the distance from the source to the nearest boundary of the convergence zone. The relations proposed by different researchers for calculating the sound speed from the temperature, salinity, and hydrostatic pressure are analyzed. It is shown that these relations lead to a substantial difference in the estimated depth dependence of the hydrostatic gradient of the sound speed. The position of the first convergence zone is calculated for the propagation conditions determined by vertical temperature and salinity profiles with the subsequent recalculation of these profiles into sound speed profiles by using eight different formulas known from the literature. It is shown that different formulas lead to different values of the distance to the first zone; this difference is substantially greater than that between the calculations and experiment. The necessity of improving the recalculation relations in view of the experimental data on sound propagation in natural oceanic waveguides, including the data on the actual positions of the convergence zones, is emphasized.     

Extracting the wavefunction of the LSP at the LHC

We consider associated production of squarks and gluinos with the lightest supersymmetric particle (LSP), or states nearly degenerate in mass with it. Though sub-dominant to pair production of color SU(3)-charged superpartners, these processes are directly sensitive to the wavefunction composition of the lightest neutralinos. Exploiting event-shape variables - including some introduced here for the first time - we are able to identify the composition of the LSP by selecting events involving a single high-pT jet recoiling against missing transverse energy. We illustrate the proposed technique on a set of benchmark cases and propose methods for applying these results in more realistic experimental environments.     

Set the controls for the heart of the Sun

In this paper we describe experiments conducted with high-power lasers that are attempting to replicate, for a very short time and in miniature, conditions found in the Sun. Experiments to date have reached conditions in the outer part of the Sun. To reach the Sun's centre requires compression of material to very much greater than solid density and heating to over ten million degrees. To achieve this, a new class of experiments and a new generation of high-power lasers are required.     

On the Question of the Source of the Apokamp

Technical Physics - The object of this work is the apokamp—a new type of plasma jet, which is formed from a bright offshoot emerging at the bending point of a channel of a high-voltage...