Motions of falling objects through air and liquid media were captured by a conventional digital camera and analyzed by a video analysis open source called Tracker. The position of the moving objects at every 33 ms was evaluated from series of images and the velocity was averaged from the change in position during each interval. For the falling in air experiment, the displacement of a ball was proportional to the time squared and the agreement with the theory was indicated by the derivation of the acceleration due to the gravity with an acceptable level of accuracy. In additions, the effects of the height of falling, the camera distance as well as the color of ball and background were investigated. In the case of falling in glycerol, the average velocity of a metal bead was initially increased with the time of falling until reaching a constant value of the terminal velocity.

We perform analytical and experimental investigation of the vertical motion of Dipterocarpus alatus seed, locally called Yang-na in Thailand. In this work, we assume the drag forces exerting on the Yang-na seeds depend only on the velocity. We derive equations of motion (EoMs) to physically parametrize the vertical motion of the seed and analytically solve to obtain the exact solutions. Interestingly, we observe that our predicted solutions are in agreement with the experimental data. More precisely, the entire trajectory of the falling seed of Yang-na can be described by our predicted solutions. We also determine terminal velocity of the seeds. Remarkably, this work reasonably proves that seed dispersal characteristics of Yang-na is inherently straight downward. Finally, we believe that our achievement will be valuable to the large community of STEM/STEAM education to promote an understanding in the topic integrating mathematics, physics, biology, art and technology.Our framework constitutes learning model to improve the ability of creative thinking, analytical thinking and problem solving skills on the concept of forces and motion applicable from high school to college levels.

The pandemic caused by the SARS-CoV-2 virus has threaten the face-to-face teaching activity in both schools and universities. The transformation from face-to-face classes to online activities yielded inefficient outcomes from the activities. Particularly, a key issue was organizing laboratory activities without accessing the labs. In this paper, we propose how to overcome this problem by enabling the students to perform physics experiments of fluid draining at home. In other words, the use of equipment commonly available at home or that can be purchased at a low price is practically plausible. In the present work, we do an experimental investigation of liquid draining through a hole of a container. From an analyzing step, we introduce a freely-accessible video analysis software, Tracker, to obtain accurate results. Interestingly, we observe the effects of viscosity causing a delay of draining time of liquids. Our study shows that a ratio of open-space radius of the container to the hole radius, √ λ, can be used to determine a draining time.