Consider a disk of mass `m`, radius `R` lying on a liquid layer of thickness T and coefficient of viscosity `eta` as shown in the fig.

The torque required to rotate the disk at a constant angular velocity `Omega` given the viscosity is uniformly `eta`.

Consider a disk of mass m , radius R lying on a liquid layer of thickness T and coefficient of viscosity eta as shown in the fig. The coefficient of viscosity varies as eta=eta_(0)x (x measured from centre of the disk) at the given instant the disk is floating towards right with a velocity v as shown, find the force required to move the disk slowly at the given instant.

Consider a disk of mass m , radius R lying on a liquid layer of thickness T and coefficient of viscosity eta as shown in the fig. A disc rotating with angularvelocity omega is placed on a viscous liquid of thickness T. Find the angle rotated by the disc before it comes to rest. (viscosity =eta , mass of disc =M , radius of disc =R )

A metal plate of area 10^(-2)m^(2) is placed on a liquid layer of thickness 2xx10^(-3)m . If the liquid has coefficient of viscosity 2 S.I. units the force required to move the plate with a velocity of 3(cm)/(s) is

A metal plate of area 10^(-3)m^(2) is placed on a liquid layer of thickness 0.8mm . The coefficient of viscosity of that liquid is 24 poise .Then the horizontal force required to move the plate with a velocity of 1cms^(-1) .

Select ALL correct answer : A disc of radius R is placed over a horizontal table in such a way that plane of the disc is horizontal and rotated about its vertical axis passing through its center with angular velocity omega . A layer of grease of thickness l is present between the table and the disc.Coefficient of viscosity of grease is eta .Then, (A) torque needed to rotate the disc with constant angular velocity is (pi eta omega R^(4))/(4l) (B) torque needed to rotate the disc with constant angular velocity is (pi eta omega R^(4))/(2l) (C) power needed to rotate the disc with constant angular velocity is (pi eta omega^(2)R^(4))/(2l) (D) power needed to rotate the disc with constant angular velocity is (pi n omega^(2)R^(4))/(4l)

A ring of mass m and radius R is being rotated about its axis with constant angular velocity omega in the gravity free space. Find tension in the ring.

A drop of water of radius r is falling rhough the air of coefficient of viscosity eta with a constant velocity of v the resultant force on the drop is

A ring of radius 'r' and mass per unit length 'm' rotates with an angular velocity 'omega' in free space then :

A small steel ball of mass m and radius r is falling under gravity through a viscous liquid of coefficient of viscosity eta . If g is the value of acceleration due to gravity. Then the terminal velocity of the ball is proportional to (ignore buoyancy)

A man is rowing a boat with a constant velocity v_(0) in a river. The contact area of boat is 'A' and coefficient of viscosity is eta . The depth of river is 'D' . Find the force required to row the boat.