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songoku
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Homework Statement
A spring has one of its end connected to the ceiling and the other end connected to the end of horizontal rod. The rod is free to rotate in xy-plane about its vertical axis. The mass of the rod is 0.6 kg and the spring constant is 2000 Nm. If the rod is displaced and undergoes small oscillations, find the period of the oscillation
Homework Equations
Not sure, maybe:
T = 2π√(I / κ)
T = 2π√(I/mgh)
τ = -κθ
τ = F . d
For small angle, sin θ = θ
I = 1/3 ML2
F = - kx
The Attempt at a Solution
My idea is to find the value of κ using τ = -κθ, then put it into T = 2π√(I / κ)
Let the rod is displaced by angle θ (where θ is small) with respect to horizontal. Is it correct that there are two forces that contribute to produce torques (weight of rod and restoring force of spring) and they act in the same direction of rotation?
I tried to do it this way and end up having term cos θ as result of finding the perpendicular distance to the pivot. I take the pivot is the end of the rod which does not connected to spring.
I think my working was wrong from the beginning...