FLUID MECHANICS EXAM 1 QUESTIONS & ANSWERS
Equation for specific weight - Answers- gamma=density x height
How is shear stress related to viscosity? - Answers- T=(dynamic viscosity)x(velocity
gradient)
Equation for torque on rotating cylinders - Answers- T=FRi
Definition of viscosity - Answers- the resistance of a fluid to flow
How does viscosity relate to temperature? - Answers- As temperature increases,
viscosity increases for a gas and decreases for a liquid
Pressure at a point (pascals law) - Answers- if there are no shear stress (no velocity
gradient) the pressure at a point is the same in all directions
Body forces are only dependent on: - Answers- gravity (specific weight of the body)
For what condition will the pressure gradient across a stream line be zero? - Answers-
If the streamlines do not curve, i.e. are straight
What is the velocity at the stagnation point on a body - Answers- V=0
At what pressure do free jets exhaust at? - Answers- P=atm=0 (gauge pressure)
What variable is neglected in a gas flow? - Answers- height
What is the velocity at the top of a large tank as it has a leak in the bottom? - Answers-
V=0 due to large tank
what is the velocity of a free jet pointing upward? - Answers- v=0 at peak
equation for flow rate - Answers- Q=AV
What happens to the velocity of a free jet as h gets larger? - Answers- The velocity
increases
Confined flows: what equation to use? - Answers- Q = constant sooo
A1V1 = A2V2
How to find pressure changes in a confined flow? - Answers- If given area changes,
you can find velocity changes by setting the flow rates equal to each other. THEN use
the Bernoulli equation to find the pressure changes
Equation for specific weight - Answers- gamma=density x height
How is shear stress related to viscosity? - Answers- T=(dynamic viscosity)x(velocity
gradient)
Equation for torque on rotating cylinders - Answers- T=FRi
Definition of viscosity - Answers- the resistance of a fluid to flow
How does viscosity relate to temperature? - Answers- As temperature increases,
viscosity increases for a gas and decreases for a liquid
Pressure at a point (pascals law) - Answers- if there are no shear stress (no velocity
gradient) the pressure at a point is the same in all directions
Body forces are only dependent on: - Answers- gravity (specific weight of the body)
For what condition will the pressure gradient across a stream line be zero? - Answers-
If the streamlines do not curve, i.e. are straight
What is the velocity at the stagnation point on a body - Answers- V=0
At what pressure do free jets exhaust at? - Answers- P=atm=0 (gauge pressure)
What variable is neglected in a gas flow? - Answers- height
What is the velocity at the top of a large tank as it has a leak in the bottom? - Answers-
V=0 due to large tank
what is the velocity of a free jet pointing upward? - Answers- v=0 at peak
equation for flow rate - Answers- Q=AV
What happens to the velocity of a free jet as h gets larger? - Answers- The velocity
increases
Confined flows: what equation to use? - Answers- Q = constant sooo
A1V1 = A2V2
How to find pressure changes in a confined flow? - Answers- If given area changes,
you can find velocity changes by setting the flow rates equal to each other. THEN use
the Bernoulli equation to find the pressure changes
