At what angle theta will both boxes begin to slide.

Wind energy is gaining increased attention, generating an increased interest in windmill technology. Because windmill blades (vanes) rotate about a central axis, one of the most important physical properties of a windmill is its moment of inertia. Given is a picture of a typical windmill, where the geometry and center of mass of one of the vanes is illustrated. The mass of each vane is 411 kg. The distance from the center of mass of the vane to axis B is ?1=2.85 m. The distance from the center of mass of the vane to the center of the windmill hub is ?2=4.42 m. If the moment of inertia of a vane about axis A is 445 kg·m2 and about axis B is 10800 kg·m2, calculate the moment of inertia ?total of the entire assembly about the axis that passes through the windmill's hub and is perpendicular to the screen. (Ignore the hub and assume the vanes are flat.)

Hello! I hope you are well.I don't understanf how we can state that the moment of Fa around B is FaL. Because as theta increases, the distance between A and B decreases : it isn't constantly L.

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