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Take Home Exam 2

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ME451Hendrik

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Unread post Sun Dec 05, 2010 7:22 pm

Take Home Exam 2

For the second take home exam due 12.7.10, I was wondering if it is to be expected that for all the methods in problems 1 and 2, including ode45, my plot continues to be a flat line of y=0. When I think about logically it seems sensible that the solution would constantly gravitate back to y=0 because the derivative is time independent. Even if I offset the initial guess in my Netwon-Raphson algorithm by a small value, the plot continues to flatline at 0. I just want to know if anyone else has had had better results.

Hendrik
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Dan Negrut

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Unread post Mon Dec 06, 2010 8:09 am

Re: Take Home Exam 2

ME451Hendrik wrote:For the second take home exam due 12.7.10, I was wondering if it is to be expected that for all the methods in problems 1 and 2, including ode45, my plot continues to be a flat line of y=0. When I think about logically it seems sensible that the solution would constantly gravitate back to y=0 because the derivative is time independent. Even if I offset the initial guess in my Netwon-Raphson algorithm by a small value, the plot continues to flatline at 0. I just want to know if anyone else has had had better results.

Hendrik


Hendrik - the second take home exam is due on December 20 at 11:59 PM.

That being said, there is a MATLAB assignment that is indeed due on 12/07/2010:
http://sbel.wisc.edu/Courses/ME451/2010 ... ment06.pdf

And here is the reason why you get a flat line: the initial condition should have been 1.0 rather than 0.  Take a look at the PDF, i made that correction.  And sorry for this mistake on my part.
Dan
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ME451Aneesh

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Unread post Sat Dec 11, 2010 8:50 pm

Re: Take Home Exam 2

Hello Prof Dan,
For the take home exam 2, I was wondering if I could assume the LRF for the body 1 to be at the center of mass.  The text assumes it to be at point at A (where it is hinged ). Since the EOM for a single body was derived with the assumption that the LRF is at the center of mass, I wanted to double check if I could proceed using the EOM derived earlier ?. Thanks.
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Dan Negrut

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Joined: Wed Sep 03, 2008 12:24 pm

Unread post Mon Dec 13, 2010 9:21 am

Re: Take Home Exam 2

ME451Aneesh wrote:Hello Prof Dan,
For the take home exam 2, I was wondering if I could assume the LRF for the body 1 to be at the center of mass.  The text assumes it to be at point at A (where it is hinged ). Since the EOM for a single body was derived with the assumption that the LRF is at the center of mass, I wanted to double check if I could proceed using the EOM derived earlier ?. Thanks.



In ME451 you should always work with LRF located at the center of mass.
Dan

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