MEASUREMENT OF LIQUID SURFACE TENSION AND AIR VISCOSITY COEFFICIENT USING DYNAMIC BUBBLE METHOD

The paper presents a device that measures the surface tension coefficient of bubble solution and the viscosity coefficient of air using the dynamic bubble method. The device captures the changes in radius and the difference in internal and external pressures during the inflation process of soap bubbles, determining the surface tension coefficient of the bubble solution through data fitting. It employs the Laplace equation and Poiseuille equation to make reasonable predictions about the changes in radius during bubble contraction. The viscosity coefficient of air can be analyzed from the data of the bubble contraction process. The device integrates the measurement of liquid surface tension coefficient and air viscosity coefficient, which can enrich and enhance students' knowledge and experimental skills. The device is also adjustable for exploration and expansion, making it suitable for college physics experiment teaching.