FLIUDS

Reynolds number determines whether or not flow can be considered compressible or incompressible.

		True
		False

False

Which property describes a fluid’s resistance to flow?

Surface tension

Specific weight

Density

Viscosity

Viscosity

The absolute Viscosity of a fluid is primarily a function of;

Density

Temperature

Pressure

Temp

Water has a density of ρ=1000 kg/m3. What is its specific weight?

1000 N/m3

981 N/m3

9.81 N/m3

9810 N/m3

9810 N/m3

All fluids are incompressible.

Tru

False

False

fluid is best defined as a substance that;

	Deforms continuously under any applied shear stress
	Has constant density
	Has a fixed volume
	Resists deformation under shear stress

Deforms continuously under any applied shear stress

Which of the following are fluid properties? Multiple selection is possible!

	Density
	Viscosity
	Pressure
	Velocity

Density and Viscosity

Which of the following are examples of Newtonian fluids?

Water Air Mercury oil

Hg and oil

Absolute pressure  is defined as:

	The difference between atmospheric pressure and gage pressure
	The pressure caused solely by the weight of the fluid
	The sum of gage pressure and atmospheric pressure
	The pressure measured relative

The sum of gage pressure and atmospheric pressure

When the absolute pressure in a system is less than atmospheric pressure, which of the following correctly defines the pressure? 

	Absolute zero pressure
	Gauge pressure
	Total pressure
	Vacuum pressure

Vacuum pressure

A barometer measures the absolute pressure of the atmosphere by balancing the atmospheric force against a column of fluid (typically Mercury)?

		True
		False

True

manometer is a Device using a liquid column to measure absolute pressure relative to vacuum.

		True
		Fals

Fals

Which of the following is a required assumption for applying hydrostatic pressure relations?

	The flow is inviscid and turbulent.
	The pressure varies with flow direction.
	The fluid velocity is uniform throughout the domain.
	The fluid is incompressible and at rest.

The fluid is incompressible and at rest. 

In a continuous mass of the same static fluid, what can be said about the pressure at two points located at the same elevation?

	The pressure is the same at both points.
	The pressure depends on the horizontal distance between the points.
	The pressure depends on the fluid velocity.
	The pressure depends on the container shape.

The pressure is the same at both points.

As you move downward (increase depth) in a liquid at rest, the pressure decreases. 

		True
		False

Flas

Fluid mechanics problems can be analyzed using either the system (Lagrangian) approach, which follows a fixed mass of fluid, or the control volume (Eulerian) approach, which focuses on a fixed region in space through which fluid flows.

		True
		False

tru

Which of the following are flow visualization methods used to describe fluid motion?

	Control volumes, systems, and boundaries
	Isobars, isotherms, and isochores
	Laminar flow, turbulent flow, and transitional flow
	Streamlines, pathlines, and streaklines

Streamlines, pathlines, and streaklines

The Hydrostatic pressure in a fluid at rest varies with: 

	Vertical distance only
	Fluid velocity
	Both horizontal and vertical distance
	Horizontal distance only

Vertical distance only

For a vertical rectangular plate submerged in water, the resultant hydrostatic force acts:

	Below the centroid
	Above the centroid
	At the free surface
	At the centroid

Below the centroid

The center of pressure is always:

	Independent of depth
	Below the centroid for vertical surfaces
	At the centroid
	Above the centroid

Below the centroid for vertical surfaces

The buoyant force acting on a submerged body equals:

	Pressure at centroid × volume
	Weight of displaced fluid
	Density of object × volume
	Weight of the object

Weight of displaced fluid

The pressure at a point in a static fluid acts:

	Only downward
	Equally in all directions
	Only upward
	Only horizontally

Equally in all directions

For a fully submerged object, the buoyant force depends on:

	Object material
	Volume displaced
	Object depth
	Object shape

Volume displaced

In a static fluid, pressure is the same in all directions at a point.

		True
		False

Tru

Hydrostatic pressure depends on the shape of the container.

		True
		False

False

Pressure decreases linearly with depth in incompressible fluids.

		True
		False

False

A system in fluid mechanics is defined as:

	Any region bounded by imaginary surfaces
	A region where mass flow rate is constant
	A fixed mass of fluid consisting of the same particles
	A fixed region in space through which fluid flows

A fixed mass of fluid consisting of the same particles

A control volume differs from a system because:

	Its mass remains constant
	It must be stationary
	It always moves with the fluid
	Fluid may cross its boundaries

Fluid may cross its boundaries

The Reynolds Transport Theorem (RTT) is used to:

	Solve only steady flow problems
	Determine density variation
	Calculate head loss
	Convert system formulations into control volume formulations

Convert system formulations into control volume formulations

Bernoulli’s equation applies to:

	Any compressible flow
	Turbulent pipe flow with losses
	Unsteady viscous flow
	Steady, incompressible, frictionless flow

Steady, incompressible, frictionless flow

Bernoulli’s equation applies to:

	Any compressible flow
	Turbulent pipe flow with losses
	Unsteady viscous flow
	Steady, incompressible, frictionless flow

No property changes with time at a fixed location

A flow is steady if:

	Flow rate is zero
	Velocity is zero
	Density is constant
	No property changes with time at a fixed location

No property changes with time at a fixed location

Volumetric flow rate depends on density.

		True
		False

False

steady flow, velocity must be constant everywhere.

		True
		False

False

If B=m (mass), the Reynolds Transport Theorem reduces to:

	Conservation of mass
	Bernoulli equation
	Angular momentum equation
	Energy equation

Conservation of mass

Which quantities can B (dummy variable for extensive properties in RTT) represent?

	Mass
	Energy
	Angular momentum
	Pressure
	Linear momentum

In steady flow, local acceleration is zero.

		True
		False

True

In a three-dimensional velocity field V(x,y,z,t), the components u,v,w represent:

	Velocity components in the Cartesian directions
	Acceleration components
	Pressure components
	Density components

Velocity components in the Cartesian directions

If the velocity components depend only on x,y,z but not on time, the flow is:

	Compressible
	Turbulent
	Inviscid
	Steady

Steady

The acceleration of a fluid particle contains: Multiple selection is possible.

	Pressure gradient
	Convective acceleration
	Local acceleration
	Divergence

Local acceleration

Convective acceleratio

Convective acceleration is associated with:

	Spatial variation of velocity
	Pressure change
	Time variation of velocity
	Density change only

Spatial variation of velocit

The velocity field V(x,y,z,t) represents:

	Pressure variation in a fluid
	Fluid motion at every point in space and time
	Velocity of a fluid particle only at the inlet
	Density distribution in a fluid

Fluid motion at every point in space and time

An infinitesimal fluid element dV represents:

	A constant fluid mass
	A differential control volume used for analysis
	A pipe cross-sectional area
	A large reservoir of fluid

differential control volume used for analysis

In incompressible flow, density can vary with time.

		True
		False

False

The material (substantial) derivative D/Dt represents:

	Change in density only
	Spatial change of pressure
	Rate of change following a moving fluid particle
	Change in velocity at a fixed point only

Rate of change following a moving fluid particle

Dimensionless Π groups are used to compare flow behavior between geometrically similar systems operating under different conditions.

		True
		False

Tru

the Buckingham Π theorem, if a problem involves n variables and m fundamental dimensions, the number of independent dimensionless groups is:

	nm
	n-m
	m-n
	n+m

n-m

The principle of dimensional homogeneity states that:

	Only SI units may be used
	All terms in an equation must have the same fundamental dimensions
	All terms in an equation must have identical numerical values
	All variables must be dimensionless

All terms in an equation must have the same fundamental dimensions

The primary purpose of dimensional analysis is to;

	Eliminate the need for governing equations
	Replace experimental testing
	Determine exact numerical solutions to fluid problems
	Reduce the number of governing variables and identify nondimensional groups

Reduce the number of governing variables and identify nondimensional groups

In the Buckingham Π method, repeating variables are best described as:

	Variables that are already dimensionless
	Variables that appear unchanged in every Π group
	Variables selected to non-dimensionalize the remaining variables
	Variables eliminated from the governing equations

Variables selected to non-dimensionalize the remaining variables

Why is the dependent variable not typically chosen as a repeating variable?

	It would automatically cancel out of the analysis
	It would prevent formation of independent Π group
	It does not contain any dimensions
	It violates dimensional homogeneity

It would prevent formation of independent Π groups

Which of the following are required characteristics of repeating variables in the Buckingham Π method? (multiple selection is possible)

They must together contain all fundamental dimensions in the problem

They must form a dimensionless group by themselves

They should be chosen to represent the dominant physics of the problem

They must include the dependent variable

They must be dimensionally independent

They must form a dimensionless group by themselves

They must include the dependent variable