What is Viscosity? Definition, Meaning & Example
Viscosity is a measure of how thick or resistant to flow a fluid is.
TL;DR: Viscosity is a measure of how thick or resistant to flow a fluid is.
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Viscosity: Viscosity is a measure of how thick or resistant to flow a fluid is.
Explanation
Viscosity describes the internal friction of a fluid that resists flow. Honey has high viscosity and flows slowly, while water has low viscosity and flows easily. Viscosity depends on temperature - warm oil flows more easily than cold oil because heat reduces internal friction. Viscosity is measured in units called poise or pascal-seconds. Understanding viscosity is important for engine oils, food production, and many industrial applications. Kinematic viscosity measures viscosity relative to density. Dynamic viscosity measures the actual resistance to flow. Shear-thinning fluids like paint have lower viscosity when stirred vigorously.
Example
Honey has much higher viscosity than water, so it flows much more slowly through a funnel.
Frequently Asked Questions
How does temperature affect viscosity?
For most liquids, viscosity decreases with increasing temperature. Heat gives molecules more kinetic energy, allowing them to flow more freely. This is why warm oil flows more easily than cold oil.
Why is viscosity important for engine oil?
Engine oil must have appropriate viscosity to lubricate engine parts effectively. Too thick and it does not flow, too thin and it does not protect. Viscosity grade rating tells you the oil thickness at standard temperatures.
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