Angular Simple Harmonic Motion

by morbidpotato
Tags: angular, harmonic, motion, simple
morbidpotato is offline
Mar16-07, 09:25 PM
P: 5
1. The problem statement, all variables and given/known data

Your boss at the Cut-Rate Cuckoo Clock Company asks you what would happen to the frequency of the angular SHM of the balance wheel if it had the same density and the same coil spring (thus the same torsion constant), but all the balance wheel dimensions were made one-third as great to save material. By what factor would the frequency change?

2. Relevant equations

frequency = 1/2(pi) * square root of (torsion constant/I)

3. The attempt at a solution

I tried finding the factor by setting up a second equation where frequency = 1/2(pi) * square root of (torsion constant/ m(r/3)^2 since I=mr^2 and got square root 3 but it didn't work. Is it because I'm using the wrong moment of inertia equation or is it something else? Please help and many thanks in advance.
Phys.Org News Partner Science news on
SensaBubble: It's a bubble, but not as we know it (w/ video)
The hemihelix: Scientists discover a new shape using rubber bands (w/ video)
Microbes provide insights into evolution of human language
denverdoc is offline
Mar16-07, 09:38 PM
P: 1,351
I thought for a thin disk the I=1/2Mr^2, if you reduce the radius by a factor of three, the I shoud will be 1/9th the original, hence...
enter260 is offline
Mar17-07, 04:08 PM
P: 8
You also have to take into account the mass that change. Since the balance wheel dimensions were made 1/3 the original, you should have 1/27 the original mass.

morbidpotato is offline
Mar18-07, 09:12 PM
P: 5

Angular Simple Harmonic Motion

thanks for the help denverdoc and enter260!

Register to reply

Related Discussions
Deriving angular frequency for simple harmonic motion Introductory Physics Homework 2
Simple Harmonic Motion Introductory Physics Homework 4
Motion of object (simple harmonic motion?) Introductory Physics Homework 3
Simple Harmonic Motion and Wave Motion General Physics 2
Simple Harmonic Motion/Wave Motion Introductory Physics Homework 2