利用智能手机磁传感器研究磁阻尼摆运动

ANALYZING MAGNETIC DAMPING PENDULUM WITH SMARTPHONE MAGNETIC SENSOR

基于Phyphox手机App,将圆柱形钕铁硼磁铁构成的单摆放在黄铜或铝板表面不同距离摆动,利用智能手机磁传感器研究磁阻尼摆运动。结果表明,相同距离下,黄铜和铝板阻尼系数基本与电导率成正比。对于铝板,磁阻尼摆离开板距离从50mm减小到18mm时,阻尼系数从1.139×10s增加到1.114×10s,随距离的变化可以用指数函数来拟合。当距离减小到2.5mm时,观察到临界阻尼现象。当磁阻尼摆离开铝板表面距离为18mm,铝板厚度从1.001mm增加到5.615mm时,磁阻尼系数从9.378×10s增加到1.967×10s。实验结果与基于磁偶极子的理论模型基本一致。本文所搭建的磁阻尼摆实验装置结构简单,研究内容丰富,特别是能定量地研究磁阻尼现象,可以作为居家物理实验开设。

The magnetic sensor in the smartphone was used to study the magnetic damping pendulum based on the Phyphox app. The cylindrical NdFeB magnetic pendulum moves at different distances above aluminum plates or brass plates. The results show that the damping coefficient is basically proportional to the conductivity of the material at the same distance. For aluminum plates, when the distance between the pendulum and the surface of the plate is reduced from 50 mm to 18 mm, the damping coefficient increases from 1.139 × 10/s to 1.114×10/s, and the change with distance can be fitted by an exponential function. When the distance is reduced to 2.5 mm, the critical damping state can be observed. As the distance between the magnet and surface of aluminum plates is 18 mm, the damping coefficient increases from 9.378×10/s to 1.967×10/s with increasing the thickness of plates from 1.001 mm to 5.615 mm. The experimental results are basically consistent with the magnetic dipole model. The experimental device is simple in structure and rich in content, especially, can be used as a home-based physical experiment to study the phenomenon of electromagnetic damping quantitatively.