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A heavy circular disc with radius R with mass M is fastened to a light string rod. The mass of the rod is negligible compared to the mass of the disc. The system can oscillate as a physical pendulum aout a fixed horizontal axis. The length of the rod is L.
Determine the period of small oscillations when the disc is fastened to the rod as shown, ie. when the disc swins in teh plane of the paper
force of gravity is [itex] mg sin \theta [/itex]
the Inertia of the disc is [itex] \frac{1}{4} MR^2 [/itex]
the inertia due to the fact that the disc is fastened to the string L is
[tex] I = \frac{1}{4} MR^2 + M (R+L)^2 [/tex]
the force due to gracvity on the CM of the disc is Mg sin theta
not quite sure how to turn that into a torque, however....
Determine the period of small oscillations when the disc is fastened to the rod as shown, ie. when the disc swins in teh plane of the paper
force of gravity is [itex] mg sin \theta [/itex]
the Inertia of the disc is [itex] \frac{1}{4} MR^2 [/itex]
the inertia due to the fact that the disc is fastened to the string L is
[tex] I = \frac{1}{4} MR^2 + M (R+L)^2 [/tex]
the force due to gracvity on the CM of the disc is Mg sin theta
not quite sure how to turn that into a torque, however....
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