(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A figure is attached.

The symmetric system consists of 4 massless rodes with length 'L',the purple thing is a spring(the spring constant is k),when the system is at rest theta=45 deg.

the system starts to rotate with angular speed 'w',the rodes are pushing on the spring and theta is getting smaller.

I need to express theta using:L,m,k,w.

3. The attempt at a solution

the length of the spring when the system is at rest is: sqrt(2)*L

so the force is: k(2*sin(theta)*L - sqrt(2)*L) = 'F'

I tried to apply newton's second law:

F = ma = m*w^2*R = 2m*w^2*Lcos(theta)

where Lcos(theta) is the radius.

but the answer is wrong..

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# Homework Help: Circular motion

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