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Hey Everyone,
I did the TBR FL3, and Passage 2 with the hydraulic press is driving me crazy.
Here is part of the passage and Qs:THe thing on the left is the reservoir (label got cut off)
8.When the flow directions of both one-way valves are reversed while the press chamber is full and the press plate is raised, the press plate:
A. descends at a gradually decreasing rate.
B. descends at a gradually increasing rate.
C. descends at a constant rate.
D. Remains stationary
Ans: A
Q9.
As fluid flows through either of the one-way valves, it
passes through a narrowed pathway. What is true of
fluid passing through the valve?
I. The fluid travels at a faster average speed than it
does through the pipes connecting the chambers.
II. The fluid exerts a greater pressure against the
valve walls than it does against the walls of the
pipes connecting the chambers.
III. The volume flow rate through the valve is the
same as the volume flow rate through the pipes
connecting the chambers.
A. I only
B . I and III only
C. II and III only
D . I , II, and III
Answer: B. Which I got and agree with but I am confused about the comparison btw the method used to solve Q8 vs. Q9, as I describe below:
So, First question:
In Q8 the solution explanation cites poiseuille's law as a way to solve the question...saying based on poiseuille's law flow rate decreases when there is a decrease in the pressure differential. Which I understand. But why is there a decrease in the pressure in this case? I don't get that.
Second Question:
The main things that is confusing me and driving me crazy is that for Q9, the solutions explanation cites Bernoulli's equation and the continuity equation. But for Q8 they used Poiseuille's.
So what gives..?? Why are they using both poiseuille (which I thought was for non ideal fluids or comparing 2 different non connected pipes) and bernoulli/continuity which I thought was for ideal fluids and a single pipe. How can they use both in this case?? In the Hydraulic Press isn't it just one connected pipe..so why does poiseuille's even apply? How do we know when to use which?
THANK YOU SO MUCH TO ANYONE WHO HELPS!
I did the TBR FL3, and Passage 2 with the hydraulic press is driving me crazy.
Here is part of the passage and Qs:THe thing on the left is the reservoir (label got cut off)
8.When the flow directions of both one-way valves are reversed while the press chamber is full and the press plate is raised, the press plate:
A. descends at a gradually decreasing rate.
B. descends at a gradually increasing rate.
C. descends at a constant rate.
D. Remains stationary
Ans: A
Q9.
As fluid flows through either of the one-way valves, it
passes through a narrowed pathway. What is true of
fluid passing through the valve?
I. The fluid travels at a faster average speed than it
does through the pipes connecting the chambers.
II. The fluid exerts a greater pressure against the
valve walls than it does against the walls of the
pipes connecting the chambers.
III. The volume flow rate through the valve is the
same as the volume flow rate through the pipes
connecting the chambers.
A. I only
B . I and III only
C. II and III only
D . I , II, and III
Answer: B. Which I got and agree with but I am confused about the comparison btw the method used to solve Q8 vs. Q9, as I describe below:
So, First question:
In Q8 the solution explanation cites poiseuille's law as a way to solve the question...saying based on poiseuille's law flow rate decreases when there is a decrease in the pressure differential. Which I understand. But why is there a decrease in the pressure in this case? I don't get that.
Second Question:
The main things that is confusing me and driving me crazy is that for Q9, the solutions explanation cites Bernoulli's equation and the continuity equation. But for Q8 they used Poiseuille's.
So what gives..?? Why are they using both poiseuille (which I thought was for non ideal fluids or comparing 2 different non connected pipes) and bernoulli/continuity which I thought was for ideal fluids and a single pipe. How can they use both in this case?? In the Hydraulic Press isn't it just one connected pipe..so why does poiseuille's even apply? How do we know when to use which?
THANK YOU SO MUCH TO ANYONE WHO HELPS!