Which branch of mechanics deals with fluids at rest?

• Dynamics

• Statics

• Fluid statics

• Kinematics

Fluid mechanics is often referred to as fluid dynamics because:

• Fluids are always in motion

• Fluids at rest are treated as a special case with zero velocity

• Fluids cannot be compressed

• All flows are laminar

Hydrodynamics primarily studies:

• Motion of gases at high speeds

• Incompressible fluid motion

• The structure of solids

• The free surface of liquids

Which distinguishes a solid from a fluid?

• Solids are heavier

• Solids resist shear stress while fluids deform continuously under it

• Solids cannot deform

• Fluids have fixed shapes

Stress in solids is proportional to strain, but in fluids stress is proportional to:

• Strain

• Strain rate

• Density

• Pressure

Liquids are generally regarded as:

• Highly compressible

• Incompressible

• Random in structure

• Without free surface

Which property distinguishes gases from liquids?

• Gases form a free surface

• Gases occupy a fixed volume

• Gases expand to fill the entire container

• Gases resist shear stress permanently

An example of a biological application of fluid mechanics is:

• Flow in open channels

• Blood flow through arteries

• Pump design

• Sediment transport

Viscosity in liquids is mainly caused by:

• Molecular collisions

• Cohesive forces between molecules

• Pressure differences

• Shear strain

The no-slip condition in fluid mechanics means:

• Fluids move faster near boundaries

• Fluids stick to solid boundaries

• Fluids slide without friction

• No shear stress acts on surfaces