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Shatzkinator
Apr30-09, 04:01 PM
1. The problem statement, all variables and given/known data
A physical pendulum consists of 4.8 m long sticks joined together as shown in Fig. 15-43. What is the pendulum's period of oscillation about a pin inserted through point A at the center of the horizontal stick?

http://edugen.wiley.com/edugen/courses/crs1650/art/qb/qu/c15/fig15_43.gif




2. Relevant equations
w = sqt(MgL/I)
T = 2pi/w
I = 1/12ml^2 + 1/3ml^2
L = l/4

3. The attempt at a solution

I solved for I using the above equation 3, solved for L using equation 4, plugged these values into equation 1 getting angular velocity. Then I solved for T in equation 2 and I do not get the correct answer.

timon
Apr30-09, 04:34 PM
you have to acount for the fact that the centre of mass of the T-shaped pendulum is positioned higher then it would with just a simple one-stick pendulum

Shatzkinator
Apr30-09, 04:40 PM
you have to acount for the fact that the centre of mass of the T-shaped pendulum is positioned higher then it would with just a simple one-stick pendulum

how do i take that into account..?

davieddy
Apr30-09, 04:49 PM
Wot: no string this time?

Shatzkinator
Apr30-09, 04:52 PM
Wot: no string this time?

What? lol

what are you asking

davieddy
Apr30-09, 05:06 PM
What? lol

what are you asking

Refererence to "string+sphere" thread.

Your pendulum seems to be more rigid, but the problem
emphasizes the impotency of the moronic reliance on formulae.

Shatzkinator
Apr30-09, 05:31 PM
Refererence to "string+sphere" thread.

Your pendulum seems to be more rigid, but the problem
emphasizes the impotency of the moronic reliance on formulae.

Yea.. that doesn't help much =P

Shatzkinator
Apr30-09, 05:53 PM
Yea.. that doesn't help much =P

Could anyone else please provide some input?

Shatzkinator
Apr30-09, 07:41 PM
anyone??

davieddy
May1-09, 01:25 AM
L is the distance between the pivot and c of m
You said "1/4"
It is 4.8m/4