### Take Home Exam 2

Hendrik

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

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

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.

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.

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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