What is Viscosity: Definition and 251 Discussions

The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water.Viscosity can be conceptualized as quantifying the internal frictional force that arises between adjacent layers of fluid that are in relative motion. For instance, when a viscous fluid is forced through a tube, it flows more quickly near the tube's axis than near its walls. In such a case, experiments show that some stress (such as a pressure difference between the two ends of the tube) is needed to sustain the flow through the tube. This is because a force is required to overcome the friction between the layers of the fluid which are in relative motion. So for a tube with a constant rate of flow, the strength of the compensating force is proportional to the fluid's viscosity.
A fluid that has no resistance to shear stress is known as an ideal or inviscid fluid. Zero viscosity is observed only at very low temperatures in superfluids. Otherwise, the second law of thermodynamics requires all fluids to have positive viscosity; such fluids are technically said to be viscous or viscid. A fluid with a high viscosity, such as pitch, may appear to be a solid.

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  1. M

    Viscosity and temperature, density is changing....

    Homework Statement Hi, I am doing physics lab on finding coefficient viscosity of fluids and how it changes by temperature by dropping a marble into fluids, finding terminal velocity, then using stoke's law to find viscosity. (using density of fluid, sphere, sphere diameter etc). The equation...
  2. B

    Calculating viscosity of a liquid with a falling object

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  3. hilbert2

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  4. K

    IB Extended Essay Ideas (viscosity)?

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  5. K

    A Deriving the Kubo Formula for Viscosity in Thermal Relativistic QFT

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  6. E

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  7. L

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  8. Chadi B Ghaith

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  9. Jabbar_B

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  10. hernando Jose

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  11. Hanyu Ye

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  12. W

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  13. Cocoleia

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  14. S

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  15. S

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  16. S

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  17. Carter Green

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  18. Titan97

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  19. T

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  20. T

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  21. C

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  22. fargoth

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  24. W

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  25. W

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  26. KingDaniel

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  27. S

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  28. O

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  30. E

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  31. avito009

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  32. D

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  33. G

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  34. S

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  35. Paulene Gueco

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  36. sheenamd1

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  37. K

    B Viscosity of Space: Theory & Evidence

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  38. Robin04

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  39. G

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  40. K

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  41. craigi

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  42. Alex299792458

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  43. H

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  44. S

    Viscosity & Pressure: Can Hydraulic Resistance Prevent Boiling?

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  45. T

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  46. R

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  47. Dennydont

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  48. F

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  49. A

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  50. W

    Droplet of ballpoint ink in water (why)

    I was wondering, a ballpoint pen ink droplet is droped on water, it floats and moves, why? Is it density, viscosity, surface tension or something else. I am pretty stuck
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