Could anyone tell me the equation for the period of the horizontal Lehman pendulum please?

Answer 1

The Lehman pendulum consists of a rod and with a mass on the end that is L from a pivot rod that has angle th w/r/t vertical. The mass swings on the rod. The force on the pendulum is m*g*sin(th). Since the frequency of osscillation is proportinal to the square root of
force per unit displacement/Inertia
if you ignore the rod, the frequency is
sqrt(g*sin(th))/L

If you include the rod of uniform denisty and mass m
sqrt(sin(th)*(M+m)*g/(M+m^2/3))/L

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