Viscosidad en fluidos Newtonianos y no Newtonianos

Why Does a Coin Sink Faster in Soap than Water?

Introduction to Viscosity

• The video begins with a question about why a coin sinks faster in soap than in water, introducing the concept of viscosity as a key property of fluids.

Objectives of the Experiment

• The main goal is to experimentally study viscosity in two Newtonian fluids (water and oil) and one non-Newtonian fluid (soap).

• Specific objectives include determining the viscosity of potable water, domestic oil, and soap, as well as obtaining values for position, time, and distance using the Tracker program.

Materials Used

• The experiment utilizes potable water from a tap, domestic cooking oil, and liquid soap. Additionally, ten marbles are used for testing.

Instruments Required

• Key instruments include an electronic balance for measuring mass, a 250 mL graduated cylinder for volume measurement, and the Tracker software for data analysis.

Experimental Procedure Overview

• Initial steps involve measuring the mass of marbles using an electronic balance and calculating their volume by displacing water in the graduated cylinder.

• A marker is used to indicate maximum fill levels without overflow during marble insertion into liquids.

Data Collection Using Tracker Software

Setting Up Tracker for Analysis

• Data collection involves importing videos into Tracker software to analyze motion. A calibration bar is inserted for reference measurements.

Tracking Motion of Marbles

• The coordinate system is set at the release point of each marble. A point mass is added to track its movement automatically.

Data Compilation

• A table displays positional data over time for each marble across different fluids (water, oil, soap), allowing velocity calculations based on distance-time relationships.

Results: Analyzing Fluid Viscosity

Velocity Measurements

• After processing video data through Tracker, tables show distances and times for marbles in each fluid. Average velocities are calculated to determine limits per fluid type.

Observations on Soap's Behavior

• Notably low velocities were observed with liquid soap compared to other fluids; this indicates higher viscosity affecting marble descent speed.

Fluid Dynamics Experiment Insights

Experimental Findings on Fluid Properties

• The experiment focused on measuring the density, velocity, and viscosity of various fluids using previously described formulas. Results indicated that liquid soap exhibited significantly higher viscosity compared to water and oil.

• Instrument precision was a concern; for instance, the ruler used to measure the marble's radius and the height of the graduated cylinder lacked accuracy, impacting results.

• Temperature variations affected experimental outcomes. The theoretical values were calculated at 20 degrees Celsius, while experimental measurements were taken at 22 degrees Celsius, leading to discrepancies in comparisons.

• Observations showed that viscosity values obtained from experiments differed from theoretical predictions due to instrument limitations and temperature effects.

• The experiment concluded with specific viscosity measurements: potable water had a viscosity of 1.410 N·s/m², domestic oil measured at 478 N·s/m², and liquid soap recorded at 24.181 m/s².

Conclusion on Viscosity Measurements