Comments on: Exam 3 information and open thread http://www.people.virginia.edu/~ejb9z/Weblog/2009/04/14/exam-3-information-and-open-thread/ The future of higher education? You. Tue, 24 Nov 2009 20:08:16 +0000 http://wordpress.org/?v=2.0.11 by: Plogger http://www.people.virginia.edu/~ejb9z/Weblog/2009/04/14/exam-3-information-and-open-thread/#comment-806 Sun, 19 Apr 2009 23:25:10 +0000 http://www.people.virginia.edu/~ejb9z/Weblog/2009/04/14/exam-3-information-and-open-thread/#comment-806 Is there an old test uploaded somewhere? Is there an old test uploaded somewhere?

]]> by: Plogger http://www.people.virginia.edu/~ejb9z/Weblog/2009/04/14/exam-3-information-and-open-thread/#comment-805 Sun, 19 Apr 2009 22:55:25 +0000 http://www.people.virginia.edu/~ejb9z/Weblog/2009/04/14/exam-3-information-and-open-thread/#comment-805 Is there an old exam uploaded somewhere? Is there an old exam uploaded somewhere?

]]> by: Plogger http://www.people.virginia.edu/~ejb9z/Weblog/2009/04/14/exam-3-information-and-open-thread/#comment-804 Sun, 19 Apr 2009 22:52:47 +0000 http://www.people.virginia.edu/~ejb9z/Weblog/2009/04/14/exam-3-information-and-open-thread/#comment-804 Is there an old exam uploaded anywhere? Is there an old exam uploaded anywhere?

]]> by: berger http://www.people.virginia.edu/~ejb9z/Weblog/2009/04/14/exam-3-information-and-open-thread/#comment-803 Sun, 19 Apr 2009 15:58:29 +0000 http://www.people.virginia.edu/~ejb9z/Weblog/2009/04/14/exam-3-information-and-open-thread/#comment-803 On the module question...I need to fix this. Done! Try it now, and sorry for the confusion. On the module question…I need to fix this. Done! Try it now, and sorry for the confusion.

]]> by: berger http://www.people.virginia.edu/~ejb9z/Weblog/2009/04/14/exam-3-information-and-open-thread/#comment-802 Sun, 19 Apr 2009 15:50:18 +0000 http://www.people.virginia.edu/~ejb9z/Weblog/2009/04/14/exam-3-information-and-open-thread/#comment-802 Okay, so on Ex. 7.3, I understand what you are saying, but the book's math is correct. Here's why. Remember that the Q calculation relies on two quantities: <ul> <li>$$A'$$: all the area on one side of the joint (in this case, above the T connection) <li>$$\bar{y}'$$: the centroid of the area $$A'$$ </ul> So the point is that the $$\bar{y}'$$ parameter does not point to the location of interest. Rather it points to the centroid of the <em>area of interest</em>. Make sense? Okay, so on Ex. 7.3, I understand what you are saying, but the book’s math is correct. Here’s why. Remember that the Q calculation relies on two quantities:

  • A': all the area on one side of the joint (in this case, above the T connection)
  • \bar{y}': the centroid of the area A'

So the point is that the \bar{y}' parameter does not point to the location of interest. Rather it points to the centroid of the area of interest. Make sense?

]]> by: Tim Ottinger http://www.people.virginia.edu/~ejb9z/Weblog/2009/04/14/exam-3-information-and-open-thread/#comment-801 Sat, 18 Apr 2009 18:53:21 +0000 http://www.people.virginia.edu/~ejb9z/Weblog/2009/04/14/exam-3-information-and-open-thread/#comment-801 Mr. Berger, I am confused in the Q calculation for problems that ask for the maximum shear stress in the glue necessary to hold the boards together along the seam where they are joined. On page 398, example 7.3, in their Q calculation, they take y' (bar) as (0.180-.015-.120)m and A' as (.03)(.150)m. The way I look at it, the shear stress should be evaluated at the joint of the two boards, where the glue is applied, and not in the middle of the board on top, because the glue wouldn't be applied 0.150m horizontally, it would be only be applied .03m across the top of the vertically standing board. The way I look at it, y'(bar) should be (.180-.03-.120). Could you clarify this? Thanks! Mr. Berger,
I am confused in the Q calculation for problems that ask for the maximum shear stress in the glue necessary to hold the boards together along the seam where they are joined. On page 398, example 7.3, in their Q calculation, they take y’ (bar) as (0.180-.015-.120)m and A’ as (.03)(.150)m. The way I look at it, the shear stress should be evaluated at the joint of the two boards, where the glue is applied, and not in the middle of the board on top, because the glue wouldn’t be applied 0.150m horizontally, it would be only be applied .03m across the top of the vertically standing board.
The way I look at it, y’(bar) should be (.180-.03-.120).
Could you clarify this?
Thanks!

]]> by: tiu2f http://www.people.virginia.edu/~ejb9z/Weblog/2009/04/14/exam-3-information-and-open-thread/#comment-800 Sat, 18 Apr 2009 05:28:27 +0000 http://www.people.virginia.edu/~ejb9z/Weblog/2009/04/14/exam-3-information-and-open-thread/#comment-800 I can't play any of the modules above I can’t play any of the modules above

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