Another Challenging ICC question!

[Wendell Swedberg]

Okays, See if you can get the answers to this ICC practice exam question:

A dwelling is located on a small hill above the street. The water main is buried in the street , 6 feet. The water service enters the house at 18 feet above the street. If the pressure at the main is 60 psi , what is the pressure at:

A) the entrance of the water service?

B) At an upstairs bathroom 26 feet above the water service entrance.

ICCs' answer is 51 psi for (A) and 38 psi for (B)......

What am I doing wrong, this is what i did:

(A) Pressure at the entrance of the water service:
18 feet - 6 feet= 12 feet
12 * .5psig = 6 psig

My answer: 60psig - 6 = 54 psig

(B) Pressure at the upstairs bathroom

For (b), 26feet -18feet = 6 feet

6feet * 0.5psig = 3 psig

My answer: 54psig - 3=51psig

[John Arnold]

The water enters the house 18 feet above the main, not the surface of the street. So 18*.5=9. 60-9=51.

The water enters the bathroom 26 feet above where it enters the house, so 26+18=44. 44*.5=22. 60-22=38.

[Jerry Peck]

The water main is buried in the street , 6 feet. The water service enters the house at 18 feet above the street.


The water enters the house 18 feet above the main, not the surface of the street.


Nope.

The water main is buried 6 feet deep below the street (question says so).

The water service enters the house 18 feet above the street (question says so).

The water service enters the house 24 feet above the main (do the math 18+6=24).

24 x 0.5 = 12

60 - 12 = 48

Looks like another bad question.

[James Duffin]

What is this .5 multiplier based on......just curious...

[Brandon Whitmore]

You lose appx. one half psi of head pressure per foot of rise in pipes.

[Scott Patterson]

Wendell, it's time to take the test! :D

[Aaron Miller]

Suggestions for future ICC exam questions:

1. Take a position for or against truth. Prove the validity of your position.

2. Define the Universe. Give two examples.

3. Disprove Einstein's Theory of Relativity. Construct an experiment to prove your position.

4. Describe the term "general knowledge" in detail. Be objective and specific.

5. Sketch the development of human thought; estimate its significance. Compare with the development of any other kind of thought.

6. The disassembled parts of a high-powered rifle have been placed in a box on your desk. You will also find an instruction manual, printed in Swahili. In ten minutes a hungry Bengal tiger will be admitted to the room. Take whatever action you feel is appropraite. Be prepared to justify your decision.

Aaron:D

[Jerry Peck]

6. The disassembled parts of a high-powered rifle have been placed in a box on your desk. You will also find an instruction manual, printed in Swahili. In ten minutes a hungry Bengal tiger will be admitted to the room. Take whatever action you feel is appropraite.

Move desk to block door shut to prevent entrance of tiger.


Be prepared to justify your decision.

Because I do not read Swahili and it will take time to assemble the high-powered rifle.

By the way - BAD question - did not state if there was any ammunition for the rifle present in the room.

Use barrel to ram down tigers throat as there was no ammunition, use stock to knock it out once it is on the floor gagging with the barrel stuck down its throat.

[Aaron Miller]

By the way - BAD question - did not state if there was any ammunition for the rifle present in the room.



Jerry:

Oh, you must've missed that in our official 2008 Exam Bulletin. It specifically states that you must arrive at the testing facility with the following:

1. Two #2 pencils.
2. A blank sheet of paper.
3. Your driver's license.
4. Another form of photo ID.
5. Rifle ammunition, sized according to your desire to pass the exam.

Aaron

[Jerry Peck]

5. Rifle ammunition, sized according to your desire to pass the exam.


BAD requirement.

I would need to know the size according to the rifle to be supplied.

When are you going to learn to write good questions and requirements? It's almost as if you intended people to 'not pass'. :D

[Aaron Miller]

When are you going to learn to write good questions and requirements? It's almost as if you intended people to 'not pass'.


BCJ:

You mean so that my firm can continue to charge you for study manuals, flash cards, code books, membership dues, re-exam fees, and such? What do you take me for anyway, a non-profit organization?

:D Aaron

[RobertSmith]

I noticed no one answered part B, pressure at the upstairs bedroom.

26 (height of upstairs bdrm) + 18 (height at service entrance) + 6 = 50feet.

50 *.5 = 25 feet.

60-25= 35 psi

[James Duffin]

In my previous life we had several (40+) water towers that kept pressure on various buildings. Every 2.31 feet of tower height gave use one pound of pressure into the building.

At times we had towers get drained due to pump problems but as soon as we got water back in the 100+ foot stand pipe we had pressure back on the building but no storage available.

I wonder how many HI undertand why towns store water in raseid towers? I bet more know now than they did before this post! :)

[Wendell Swedberg]

are you sure it's done that way for (b)?

Is it not just 50*.5 = 25 psig for the upper fixture????

[Jerry Peck]

Wendell,

You have to take you total height above the main (50 feet) times the pressure loss per foot of height (0.5 psi) = 25 psi, then subtract that from the starting pressure at the main (60 psi), which leaves the pressure at the fixture (60 psi less 25 psi = 35 psi)