Welcome to the website of ME 274 for the Fall 2008 semester. On this site you can view blog posts, add your own blog posts and add comments to existing posts. In addition to the blog are links to course material: course information, information on solution videos, exams, quizzes, homeworks and other course-related material. Direct links to the homework solution videos are also available on the left side of this page.


The following is a reverse chronological order listing of the posts for the course blog. To add a post, click here (when adding posts, be sure to add a "label" in the box at the lower right side of the post window). To add a comment to an existing post, click on the "Comments" link below the post.


____________________________________________________

Oct 29, 2008

Problems 3/236 and 3/248

Professor

In prob 3/236 we considered a conservation of angular momentum and you said in the solution that we can neglect the moment caused by the weights . But i noticed that for nearly the same case in problem 3/248 we used the work-energy equation in the end because there is a moment caused by the weights.
Can you please clarify this further?

Thank you
Posted by at

2 comments:

CMK said...

Weight is a force that is present during all time for both Problems 3/236 and 3/248. Impact forces tend to be much larger than the weight force (typically an order of magnitude larger). Therefore the impulse due to an impact force is much larger than the impulse due to weight. Because of this we neglect weight DURING impact. For all other time (such as BEFORE impact in Problem 3/236 and AFTER impact in Problem 3/248) we include weight.

Does this help?

Good question.

October 29, 2008 at 10:55 AM
nour said...

Yes it s clear now thank you.

October 29, 2008 at 11:16 AM

Post a Comment

Subscribe to: Post Comments (Atom)