Under standard conditions helium fills up the space between two long coaxial cylinders. The mean radius of the cylinders is equal to `R`, the gap between them is equal to `Delta R`, with `Delta R lt lt R`. The outer cylinder rotates with a fairly low angular velocity `omega` about the stationary inner cylinder. Down to what magnitude should the helium pressure be lowered (keeping the temperature constant) to decrease the sought moment of friction forces `n = 10` times if `Delta R = 6 mm` ?

A gas fills up the space between two long coaxial cylinders of radii R_1 and R_2 , with R_1 lt R_2 . The outer cylinder rotates with a fairly low angular velocity omega about the stationary inner cylinder. The moment of friction forces acting on a unit length of the inner cylinder is equal to N_1 . Find the viscosity coefficient eta of the gas taking into account that the friction force acting on a unit area of the cylindrical surface of radius r is determined by the formule sigma = eta r(del omega//del r) .

A homegoneous poorly condcuting medium of resistivity rho fills up space between two thin coaxial ideally conducting cylinder is l . The radii of the cylinders are equal to a and b with a lt b , the length of each cylinder is l . Neglecting the edge effects , find the resistance of the medium between the cylinders.

A cylinder of mass M, radius r_(1) and lenglth l is kept inside another cylinder of radius r_(2) and length l. The space between them is filled with a liquid of viscosity eta . The inner cylinder starts rotating with angular velocity omega while the other cylinder is at rest. Find time when inner cylinder stops.

A solid cylinder of mass M and radius R rotates about its axis with angular speed omega . Its rotational kinetic energy is

A solid cylinder of mass M and radius R rotates about its axis with angular speed omega . Its rotational kinetic energy is

A fluid with viscosity eta fills the space between two long co-axial cylinders of radii R_1 and R_2 , with R_1 lt R_2 . The inner cylinder is stationary while the outer one is rotated with a constant angular velocity omega_2 . The fluid flow is laminar. Taking into account that the friction force acting on a unit area of a cylindrical surface of radius r is defined by the formula sigma=etar(delomega//delr) , find: (a) the angular velocity of the rotating fluid is as a function of radius r, (b) the moment of the friction forces acting on a unit length of the outer cylinder.

There are two concentric cylinders of radii R_(1) and R_(2) as shown. The narrow space between the two cylinders is filled with liquid of viscosity mu . The inner cylinder is held stationary by means of a torsional spring of stiffness G. the outer cylinder is rotated with constant angular speed omega . The torque acting on the inner cylinder due to shearing action of thhe liquid:

There are two concentric cylinders of radii R_(1) and R_(2) as shown. The narrow space between the two cylinders is filled with liquid of viscosity mu . The inner cylinder is held stationary by means of a torsional spring of stiffness G. the outer cylinder is rotated with constant angular speed omega . The torque acting on the inner cylinder due to shearing action of thhe liquid:

The radius of a sphere and a circular cylinder is r. If their volumes are equal, the height of the cylinder will be

A current I flows in a long thin walled cylinder of radius R . What pressure do the walls of the cylinder experience ?