Created By : Naaz Fatima

Reviewed By : Phani Ponnapalli

Last Updated : May 18, 2023


After entering the inputs viscosity, fluid density, and particle density and diameter, the Free Online Stokes Law Calculator determines the terminal velocity in a fraction of a second. Make your calculations simple and get the ultimate velocity of the object quickly by using the handy calculator.

Choose a Calculation
Medium viscosity(µ):
Medium density(ρ_m):
Particle density(ρ_p):
Particle diameter(d):
Acceleration due to gravity(g):

Viscosity - Definition

The resistance to shearing forces of a fluid (gas or liquid) is measured by its viscosity. For example, Honey has a far higher viscosity than water hence it is more resistant to shear forces. Pascals per second (Pas) are the units of viscosity. Consider a stream of water and honey moving down the slope to get a sense of how viscosity influences a liquid. Due to its low viscosity, water moves quickly. Honey will flow slowly due to its very low viscosity.

Stokes Law Terminal Velocity Formula

The terminal velocity of a particle in a viscometer filled with a viscous fluid is defined by the Stokes law as follows v = gd²(ρp - ρm)/(18μ)

  • Where, v = terminal velocity of a spherical particle
  • g = gravitational acceleration and is equal to 9.80665 m/s²
  • d = diameter of the particle
  • ρp = density of the particle
  • ρm = density of the fluid
  • μ = dynamic viscosity of the fluid

How do you use Stokes Law to calculate Terminal Velocity?

To find terminal velocity using the Stokes law, follow the easy steps below. As so, they are

  • Step 1: To begin, determine the particle's diameter.
  • Step 2: Next, look at the particle's density.
  • Step 3: After that, find out the fluid's density and viscosity.
  • Step 4: To get the terminal velocity, simply plug all of these parameters into the equation.
  • Step 5: Simplify the equation, even more, to rapidly determine the terminal velocity.

How do I use the Stokes Law Calculator?

The process for using the stokes law calculator is as follows

  • Step 1: Input the unknown's viscosity, fluid density, and particle density and diameter, and x in the appropriate input fields.
  • Step 2: Select the "Calculate unknown" option to calculate the terminal velocity.
  • Step 3: Finally, the terminal velocity of the object will be displayed in the output field.

For more concepts check out physicscalculatorpro.com to get quick answers by using this free tool.

FAQs on Stokes Law

1. What exactly is Stokes Law?

According to Stokes Law, a force that retards a sphere travelling through a viscous fluid is proportional to the radius of the sphere, the viscosity of the fluid, and other factors.


2. How to find Terminal Velocity?

The formula v = gd2(p - m)/(18) can be used to calculate terminal velocity.


3. What exactly is Stoke's law, and when does it apply?

Stoke's Law is applicable under the following conditions: 1) The law applies to a fluid of unlimited extent. 2) If the spherical body is moving so quickly that conditions are not streamlined, the law does not apply. 3) The smooth and rigid spherical body is required.


4. What is the settling velocity Stokes law?

The particle sedimentation velocity is related to the density difference between the solid and liquid phases, inversely proportional to the liquid viscosity, and proportional to the square of particle diameter.


5. How do you find Terminal Velocity in Stokes law?

The terminal velocity of a sphere of radius r and density immersed in a liquid of density and viscosity is given by v=29(ρ−σ)r2gη.


6. Has the Navier-Stokes equation been solved?

The Navier–Stokes equations, in particular, frequently incorporate turbulence, which, despite its importance in research and industry, remains one of the greatest unsolved issues in physics. Even more fundamental (and seemingly intuitive) characteristics of Navier–Stokes solutions have never been demonstrated.


7. What does the term viscosity mean?

A fluid's viscosity is defined as its resistance to shearing stresses.