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.


____________________________________________________

Mar 29, 2008

Homework Hint: Problem No. 6/129

Here you need to write the total KE of the system as a SUM of the KE's for each component individually (yoke and wheel). This KE expression will involve angular velocities for each component. These angular velocities are NOT equal; however, they are related through a CONSTRAINT. The constraint here is that point A exists on each component. Write the expression for the velocity of A on the wheel and equate it to the expression for the velocity of A on the yoke. This equation will give the needed relationship between the angular velocities of the yoke and wheel.

4 comments:

Sebastien Planquois said...

I am having troubles applying the radius of gyration in the Io term of the equation, could anyone give me a hint?
Appreciate it.

CMK said...

The mass moment of inertia about point O can be found from:

I_O = m*k_O^2

where m is the mass of the yoke (3 kg) and k_O is the radius of gyration about O ( 0.350 meters).

mheida said...

I am confused about which two velocities of A to relate. The origional hint states both as the wheel, and I assumed that meant a v(a)=v(o) and v(a)=v(g) equations with omegas included. But for me to finish solving, in need to also use a v(g)=v(o) equation. Is this correct, or is there a simpler method?

CMK said...

My goof (for not proofing what I typed).

I intended to say to equate the velocity of A on the wheel to the velocity of A on the yoke. That is, write:

v_A = v_C + omega_wheel x r_A/C
v_A = v_O + omega_yoke x rA/O

where C is the contact point of the wheel with the circular surface. Equate these to to relate omega_wheel and omega_yoke.

Sorry for the confusion created by the mistyping.