The velocity of water in a river is:

$A$ plastic circular disc of radius $R$ is placed on a thin oil film,spread over a flat horizontal surface. The torque required to spin the disc about its central vertical axis with a constant angular velocity is proportional to

Why do machine parts become sticky in winter?

$A$ cubical block of side $a$ and density $\rho$ slides over a fixed inclined plane with constant velocity $v$. There is a thin film of viscous fluid of thickness $t$ between the plane and the block. If the angle of inclination is $37^{\circ}$,then the coefficient of viscosity of the thin film will be:

Explain velocity gradient and coefficient of viscosity and give their units.

As the temperature of water increases,its viscosity