Normal Modes Question

  • #1
benij_chaos
3
0
I Have a question that is bugging me because I can't get the answer out here's the question:

A uniform rod of length a hangs vertically on the end of an inelastic string of length a, the string being attached to the upper end of the rod. What are the frequencies of the normal modes of oscillation in the vertical plane.

Any help would be appreciated thanks
 

Answers and Replies

  • #2
Gokul43201
Staff Emeritus
Science Advisor
Gold Member
7,176
21
benij, it is required that you show your thoughts/efforts when asking for help with coursework/textbook problems.
 
  • #3
benij_chaos
3
0
I set the problem up with two angles, one that joins the string to the vertical and one that joins the string to the rod. My problem comes in not knowing how treat the mass in the question. I have tried dividing it up into two parts and that does not seem to work. I am effectively stuck before I am started.
 
  • #4
Gokul43201
Staff Emeritus
Science Advisor
Gold Member
7,176
21
Can you find the velocity of the center of mass of the rod, in terms of the lengths and angles (and their derivatives)? From v(COM) and the angular velocity about its top end, you can then write down the total kinetic energy term, T.

PS: I don't know what 2 masses you are talking about. The string is massless.
 
Last edited:

Suggested for: Normal Modes Question

  • Last Post
Replies
10
Views
423
  • Last Post
Replies
1
Views
179
  • Last Post
Replies
2
Views
355
Replies
11
Views
683
Replies
11
Views
576
Replies
1
Views
457
Replies
1
Views
422
Replies
2
Views
1K
Replies
3
Views
630
Replies
15
Views
381
Top