Mechanical Engineering - Hydraulics and Fluid Mechanics - Discussion

Yes, I agree with the given answer.

It is cohesive forces (forces between atoms/molecules of the same type eg water to water) which are important not adhesive forces (forces between atoms/molecules of different type eg water to glass).

Dynamic viscosity of water is less than that of mercury. But kinematic viscosity of water is higher than that of mercury, this is because mercury is a lot denser than water. Kinematic viscosity is the ratio of dynamic viscosity and density.

The viscosity of mercury is lesser than the water because shear stress developed in water is more than mercury, this is taken from the relation viscosity is directly proportional to the shear stress and inversely proportional to velocity gradient.

Hello, guys.

Viscosity is internal fluid friction which causes to flow, and also an origin of viscosity is due to cohesive force (in liquid) & molecular momentum transfer (in gas).

So by this, cohesive force in mercury is greater than in water, it means that molecule of mercury offers more resistance to flow as compare to water, that's why absolute viscosity of mercury is greater than water.

For kinematic, its just reverse because in kinematic viscosity, density divide the absolute viscoty

If I'm wrong, please suggest me.

Kinematic viscosity of mercury is less than of water. But dynamic viscosity is greater.

The Kinematic viscosity is the ratio of dynamic viscosity and density. And mercury is more denser than water.

Viscosity of water = .01 poise and viscosity of mercury = .016 poise.

Dynamic viscosity of mercury is more than dynamic viscosity of water but kinematic viscosity is less because of mercury is denser than the water.

Viscosity of mercury is more than that of water.

Viscosity of water is more than that of water because water is more adhesive than mercury.