The added mass of a falling coffee filter

Abstract Falling coffee filters are a common object of study in introductory physics laboratory classes. They usually used to demonstrate the terminal velocity, and determine how drag force depends on this velocity. However they can also be other ways that air affects motion falling filter. In particular, qualitatively different fluid acts during initial acceleration from rest, causes much less than an vacuum. This force, commonly known as ‘added mass’, is easily observable with using either sonic sensor or video analysis. Here added mass experimentally measured for addition, theoretical value filter moving through ideal calculated. The two values agree relatively well. Finally, it shown relevant experiments only measure