Clock Oscillation: Q Calculation for 0.7 m Pendulum w/ 0.4 kg Bob

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SUMMARY

The discussion focuses on calculating the quality factor (Q) of a grandfather clock's pendulum system with a length of 0.7 m and a bob mass of 0.4 kg. The relevant equations for Q are provided, specifically Q = ωR/2β and Q = ω0/Δω. The user attempts to derive Q using the damping coefficient (b) but encounters difficulties in determining its value. The energy provided by a 2 kg mass falling 0.8 m over seven days is crucial for understanding the system's damping and oscillation stability.

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Homework Statement



A grandfather clock has a pendulum length of 0.7 m and a mass bob of 0.4 kg. A mass
of 2 kg falls 0.8 m in seven days, providing the energy necessary to keep the amplitude
(from equilibrium) of the pendulum oscillation steady at 0.03 rad. What is the Q of the
system?

Homework Equations



1) Q = [tex]\omega[/tex]R/2[tex]\beta[/tex]

2) Q = [tex]\omega[/tex]0/[tex]\Delta[/tex][tex]\omega[/tex]

The Attempt at a Solution



I figured only equation 1 would help me here, and I can re-arrange it as follows:

[tex]\beta[/tex] = b/2m (b = damping coefficient)

Then Q = m[tex]\omega[/tex]R/b

when amplitude D is a maximum, we can differenciate wrt [tex]\omega[/tex] to obtain maximum (i.e [tex]\omega[/tex]R)

[tex]\omega[/tex]R = sqrt([tex]\omega[/tex]20 - 2[tex]\beta[/tex]2)

re-arranging yields

Q = m sqrt([tex]\omega[/tex]20 - b2/2m2)/b

I'm kind of stuck because I don't know how to find the coefficient of damping b. Did I go in the wrong direction here? I know I have to use the information given about the pendulum dropping to find the flaw in the system, any help please?
 
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While I'm not certain how to solve the problem, the 2 kg mass dropping tells us at what rate energy is added to the pendulum to overcome damping.

Also, the power dissipated due to damping is definitely related to b. If you can express that power in terms of b, you should be in good shape.
 

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