<![CDATA[In this study, a motion-tracking analysis method was applied to a viscometry system to measure free-fall velocity and determine the viscosity of a fluid. Experiments were conducted by dropping a marble into a tube containing the test liquid with known density, then recording its free-fall motion with a digital camera at 30 frames per second and analysing the data with Tracker software. From the calculated terminal velocity analysis across two trials ((7.46 ± 0.01) × 10-4 m/s and (8.64 ± 0.01) × 10-4 m/s), the viscosity values obtained were 3.0 Pa·s and 2.59 Pa·s, respectively, which are well within the acceptable range. An alternative approach using exponential curve fitting to analyse the transient phase did not yield results as accurate or comparable to the previous, because the data showed a linear relationship between position and time. In two consecutive trials, the viscosity values calculated using this method are 2.81 × 10-2 Pa·s and 3.02 × 10-2 Pa·s. This condition was likely caused by the camera's limited frame rate, which was insufficient to capture the continuous, subtle changes in downward velocity during the first phase of free-fall motion, which occurred over a very short period. Therefore, in a basic, simple yet standard experimental setup, viscosity can be reliably calculated only by measuring the terminal velocity in accordance with Stokes' law.]]>
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