双车法演示实验中抵消摩擦力的分析

Analysis of offsetting friction in double-car demonstration experiment

考虑了用双车法演示牛顿第二定律实验中被忽略的因素,理论分析得出了斜面倾角与小车质量等因素的关系,并通过实验验证了小车质量发生变化后需要重新调节倾角的结论,同时指出在实验中应如何选择实验器材减小小车质量的变化对实验的影响.

Double-car demonstration experiment is used to demonstrate Newton second law in the senior physics teaching. It is necessary to research further on the generation of friction in the experiment. A formula which contains the dip angle, the mass of the car and the deformation of the inclined plane is obtained with theoretical analysis. It is proved experimentally that the dip angle should be adjusted when the mass of the car is changed. According to the formula, the effect of mass change of the car can be almost eliminated by choosing hard material to make the inclined Diane.