ANALYSIS OF THE FALLING MOTION OF A SOLID BALL AND COIN IN HOMOGENOUS FLUID AND STRATIFICATION FLUID USING VIDEO TRACKER

• Main Author: Nurta, Nopizon
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/71399
• Institution: Institut Teknologi Bandung

The problem of falling motion of objects dropped freely in a fluid needs further testing and analysis to obtain information related to the kinematics of its motion. The fluid in question is a liquid at rest in a cylindrical tube (static fluid). This study aims to determine the position at any time yt and the velocity at any time vt of the motion of an object in the fluid and to analyze the effect of variations in the type of fluid on its position and velocity. Data was collected by dropping 2.02 grams of solid balls with a density of 8.783 g/cm3 and dropping 1.79 grams of coins with a density of 2.103 g/cm3 and keeping them stationary on the surface of the fluid (the density of fluids is always smaller than objects) in a 1000 mL cylindrical tube. with a height of 36 cm and recorded using a camera with 1080p 250fps video quality. Homogeneous fluids contain only one type of fluid, namely 1000 mL water, 1000 mL glycerin and 1000 mL oil, while stratified fluids contain 2 types of fluids namely stratification (500 mL water + 500 mL oil), stratification (500 mL water + 500 mL glycerin) and stratification (500 mL oil + 500 mL glycerin). Video recordings of solid ball and coin motions are processed using Software Tracker to obtain traces of the solid ball and coin movements every time yt and the speed of each time vt and the angle of rotation every time ?t for the motion of the coins. The results of the analysis show that the motion of a solid ball in a homogeneous fluid moves accelerated and then reaches a terminal velocity, whereas in a stratified fluid it initially moves accelerated, but not in all types of fluids a terminal velocity is obtained because the presence of a boundary area causes a change in velocity. The results of the analysis of the motion of coins experience complex motion, and are affected by alternating rotational motion, even in one type of fluid forming a zig zag motion pattern. The effect of rotational motion on the coin decreases as the viscosity coefficient of the homogeneous fluid increases. Meanwhile, in the starting fluid in each phase 2, the effect of rotational motion on the coins no longer occurs.