Please help me make sense of this question in plumbing textbook

[sevensages]

TL;DR Summary: I need to make sense of this question: What was the distance from the line-of-sight of the builder's level to the outlet end of the first 10' length of pipe?

I am enrolled in an online course in plumbing at Stratford Career Institute. At the end of each chapter in my plumbing textbook, there is a test for that chapter. I am totally baffled by one of the questions on the test for a chapter about leveling instruments used in plumbing. Stratford Career Institute sent me an answer key to the question. So I know the correct answer to the question. But I have no idea why the correct answer is the correct answer. I don't understand the test question at all. I think that some of the people here at PF could help me with this for two reasons: 1# A lot of you people would be far more knowledgeable about plumbing (and about physics) than I am and 2# A lot of you are far more intelligent than I am.

The instructions for the test question are the following: "Refer to figures 5-8, 5-9, and 5-10, and the discussion of the process of laying 4 1/2" diameter pipe in the trench."

Here is the actual question that I am baffled by: "What was the distance from the line-of-sight of the builder's level to the outlet end of the first 10' length of pipe?"

I will post photograph of the pages of the textbook with figures 5-8, 5-9, and 5-10, and the discussion of the process of laying 4 1/2" diameter pipe in the trench.

Here are the photographs:

Please ignore the smiley faces in those photographs. I only added the smiley faces because I had to edit those photographs in order to get them to face the correct direction. I created an entire thread about this problem in the feedback section entitled "PhysicsForums is rotating my photographs".

Here is a photograph of the question I am asking about in the textbook. I just need feedback on question 1A.

 

[sevensages]

I have trouble reading the text on my photograph of page 96. I hope you all can read it.

 

[sevensages]

I am going to post page 96 in three different photographs to get higher resolution.

Part of the text of figure 5-9 is not included in the photograph. So I will give a transcript of the text of Figure 5-9 here: Figure 5-9 The first step in installing a branch sewer line is to sight through the level, finding the difference in height between the branch from the building and the sewer tap.

 

[sevensages]

The resolution on page 97 on the OP is crummy as well. The only part of page 97 relevant to the test question is figure 5-10. Here is a higher resolution photograph of figure 5-10 on page 97:

 

[sevensages]

The answer to the question of the OP is 8' 6 1/2" . But what does the test question mean? And how does one get to the answer of 8'6 1/2"?

 

[PeterDonis]

Moderator's note: Thread moved to the Engineering homework forum. @sevensages you need to show some effort at working the problem yourself.

 

[sevensages]

I just noticed that the discussion of the process of laying 4 1/2" diameter pipe has the EXACT scenario of the question described in it LOL-----The book answers the question. The question of the OP is answered.

 

[PeterDonis]

I have trouble reading the text on my photograph of page 96. I hope you all can read it.

I have trouble reading all of your photographs. I suggest posting the question directly in this thread, using the LaTeX feature for equations.

 

[sevensages]

I have trouble reading all of your photographs. I suggest posting the question directly in this thread, using the LaTeX feature for equations.

The photographs I posted in posts #3 and #4 on this thread are fairly clear. But like i said, the text answers the question of the OP.

 

[PeterDonis]

The photographs I posted in posts #3 and #4 on this thread are fairly clear.

Maybe they are to you. They aren't to me. Generally speaking, while photos are helpful as background information, actual questions are best posted directly in the thread, using LaTeX for equations, as I said. That allows the text and equations to be quoted in replies, as well as making them much easier to read.

 

[Tom.G]

On page 96, section 5.1.1, have you understood steps 1 thru 4 at the bottom of the page?

Have you answered step 4? If so, please supply the answer you came up with.