What is the definition of Stokes law in physics?
What is the definition of Stokes law in physics?
Stokes’ law is a law in physics that states that the force that resists a sphere’s fall in a viscous fluid is directly proportional to the velocity of the sphere, the radius of the sphere, and the viscosity of the fluid. r is the radius of the sphere.
What is Stokes law derive its formula?
According to Stokes law, if a spherical body falls into a viscous liquid then the force acting at the interface is proportional to – Radius of the spherical body, velocity of the sphere, and viscosity of this given fluid.
What is Stokes law explain it with figure?
Stokes’s law, mathematical equation that expresses the drag force resisting the fall of small spherical particles through a fluid medium. Stokes in 1851, is derived by consideration of the forces acting on a particular particle as it sinks through a liquid column under the influence of gravity.
What is Stokes law in physics class 11?
Stokes Law. Stokes Law. The force that retards a sphere moving through a viscous fluid is directly ∝to the velocity and the radius of the sphere, and the viscosity of the fluid.
Why do we use Stokes law?
Stokes’ law is the basis of the falling-sphere viscometer, in which the fluid is stationary in a vertical glass tube. Knowing the terminal velocity, the size and density of the sphere, and the density of the liquid, Stokes’ law can be used to calculate the viscosity of the fluid.
What is Stokes law What are the condition of Stokes law?
Conditions under which Stoke’s law is valid are: The fluid through which the body moves must have infinite extension. The body is perfectly rigid and smooth. There is no slip between the body and the fluid. The motion of the body does not give rise to turbulent motion.
How do you find viscosity in Stokes law?
He found what has become known as Stokes’ Law: the drag force F on a sphere of radius a moving through a fluid of viscosity η at speed v is given by: F=6πaηv. Note that this drag force is directly proportional to the radius.
What do you mean by Stokes law in laminar flow?
Stokes Law, named after George Gabriel Stokes, describes the relationship between the frictional force of a sphere moving in a liquid and other quantities (such as particle radius and velocity of the particle). If a sphere or a body moves through a fluid, a friction force must be overcome.
What do you mean by viscosity derive expression for it?
Formally, viscosity (represented by the symbol η “eta”) is the ratio of the shearing stress (F/A) to the velocity gradient (∆vx/∆z or dvx/dz) in a fluid. η = F/A.
What is Stoke’s law in soil mechanics?
Stokes law is based on the assumption that all the soil particles are spherical. specific gravity of solids for different particles is different, but we use its average value. 3. Stokes law is applicable when fall of particle is in the liquid which has infinite extent, that is no boundary is present.
How do you explain Stokes Theorem?
Stokes’ Theorem Formula The Stoke’s theorem states that “the surface integral of the curl of a function over a surface bounded by a closed surface is equal to the line integral of the particular vector function around that surface.”
What is Stokes law for settling velocity?
According to Stokes’ law, the particle sedimentation velocity is proportional to the density difference between the solid phase and the liquid phase, inversely proportional to the viscosity of the liquid, and proportional to the square of particle diameter.
How does Stokes law relate to viscosity and velocity?
Stokes’ law defines the drag force that exists between a sphere moving through a fluid with constant velocity. Viscosity is the resistance of a fluid to flow, and with increasing viscosity, the sphere’s velocity drops. When the radius of the sphere increases, the drag force increases too.
Which is an example of the Stokes law?
Define Stokes Law with an Example. Ans. According to Stokes law, if a spherical body falls into a viscous liquid then the force acting at the interface is proportional to – Radius of the spherical body, velocity of the sphere, and viscosity of this given fluid.
How is Stokes law used in falling sphere viscometer?
Stokes law is the basis of the falling-sphere viscometer, in which the fluid is stationary in a vertical glass tube. A sphere of known size and density is allowed to descend through the liquid.
How is FD used in the application of Stokes law?
FD is the drag force on the sphere falling through the fluid in newtons (N) This equation tells us that the larger the ball bearing, the larger the force on it when it is moving through a fluid at terminal velocity. This is where an application of Stokes’ law comes in dealing with something we have all experienced: fog and rain.
