Page:Great Neapolitan Earthquake of 1857.djvu/174

126 where $$\omega$$ is the angular velocity of the body at starting, $$k$$ the radius of gyration, with respect to the point or arris on which it turns, and $$g$$ the velocity acquired by a falling body in one second of time.

Equating these two values of the work done we find but $$\omega$$, the angular velocity, is equal to the statical couple applied, divided by the moment of inertia, or squaring and substituting  and since the length of the corresponding simple pendulum is   In order to apply this formula to any given case we must determine the corresponding value of $$l$$, the simple pendulum applying to that case.



1st. In the case of a solid cube overturned (Fig. 94) whose side is $$\alpha$$;