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viscosity of liquid

Viscosity Of Liquid Experiment Falling Sphere

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Introduction to the Viscosity of Liquid Experiment Falling Sphere

Viscosity is a measure of the resistance of a fluid which is being deformed by either shear stress or tensile stress.

In everyday terms (and for fluids only), viscosity is “thickness”. Thus, water is “thin”, having a lower viscosity, while honey is “thick”, having a higher viscosity, viscosity is also defined as the resistance of a fluid (liquid or gas) to a change in shape or movement of neighboring portions relative to one another.

Aim of The Experiment

To deduce the coefficient of viscosity for a liquid.

Tools of The Experiment

  • A long glass tube about 50 cm long closed at one end.
  • Liquid.
  • Meter Scale.
  • Small Sphere.
  • Magnet.
  • Stop-Watch.
  • Rubber Band.

Steps And Method of The Experiment

  • Adjust the distance between the rubber bands.

1-Recored the distance (h) between them (30cm).

2-Drop a sphere centrally down the tube.

3-With the stop-watch find the time it takes to traverse the distance between the two bands.

4-Obtain two values of the time of fall and take the mean t-mean.

5-Repeat for different values of (h).

Coefficient of Viscosity Liquid Experiment: Theory and Final Law

Parameters, Theory & Final Law

ρ
Density of the sphere
d
Diameter of the sphere
σ
Density of the liquid
v
Velocity
h/cm t/sec slope = h/t
Slope = ht = velocity cm/sec
Final Law

Viscosity of liquid:

η = g(ρ − σ)d2 18v

Table of The Readings

Table of the Readings

Distance between rubber bands
h/cm		 Time of fall
t1/sec t2/sec t mean/sec

Medical Application

Understanding the viscosity of liquid experiment falling sphere principles has direct clinical relevance to blood flow.

Viscosity of blood increases as the hematocrit increases, such as in the disease polycythemia vera, where the body produces an excess of red blood cells. Since red blood cells are the primary contributor to blood’s resistance to flow, this elevated hematocrit directly increases how thick and resistant to flow the blood becomes, forcing the heart to work harder to circulate it. Viscosity also increases as temperature decreases, which is why cold hands and feet receive comparatively less blood supply — the cooler, more viscous blood flows less readily through the narrow peripheral vessels, and this same temperature-viscosity relationship is exactly what the viscosity of liquid experiment falling sphere is designed to demonstrate and measure.

Frequently Asked Questions About the Viscosity of Liquid Experiment Using a Falling Sphere

Q: What does the viscosity of liquid experiment falling sphere actually measure?

This viscosity of liquid experiment falling sphere method determines a liquid's resistance to flow by timing how long it takes a small sphere to fall a fixed distance through the liquid, then using that fall time to calculate the coefficient of viscosity.

Why is a magnet included as one of the tools in the viscosity of liquid experiment falling sphere?

It's used to retrieve the small metal sphere from the bottom of the tube after each trial in the viscosity of liquid experiment falling sphere, allowing it to be reused for repeated measurements without disassembling the setup.

Why measure the time of fall at multiple values of h in the viscosity of liquid experiment falling sphere?

Taking readings at several distances lets you plot h against t and calculate velocity from the slope of the line — a more reliable result than relying on a single timed drop in the viscosity of liquid experiment falling sphere, which is more susceptible to reaction-time error.

How does the viscosity of liquid experiment falling sphere relate to blood viscosity in conditions like polycythemia vera?

The same physical principles measured in the viscosity of liquid experiment falling sphere apply to blood: since red blood cells are the primary contributor to blood's resistance to flow, a higher hematocrit — as seen in polycythemia vera — directly increases blood viscosity.